Unprecedented Warming in Lake Tanganyika

Lake Tanganyika from space, June 1985

Well here we go again, you know the drill. Global warming at fault, other possibilities ignored, multiple press releases. Lake Tanganyika is the second largest lake in the world for fresh water, so naturally any change it is cause for “alarm”. Unfortunately in these press releases there is no mention of a possible increase in turbidity due to human action on and around the lake, decreasing the albedo to absorb more sunlight on the lake surface, warming it. At least somebody has already asked that question previously in peer reviewed literature where they describe the Lake Tanganyika problem as “watershed deforestation, road building, and other anthropogenic activities result in sediment inundation…“.

But in our current press releases, there is this hat tip to anthropogenic: “The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.

First from Brown University:

Brown Geologists Show Unprecedented Warming in Lake Tanganyika

Reeling in the big one. Researchers drilled cores into Lake Tanganyika to document the lake’s surface temperature for the last 1,500 years. They found unprecedented warming in the 20th century. Brown geologist James Russell, kneeling at drill head, led this core sampling mission in 2004. Credit: Kate Whittaker

PROVIDENCE, R.I. [Brown University] — Lake Tanganyika, the second oldest and the second-deepest lake in the world, could be in for some rough waters.

Geologists led by Brown University have determined the east African rift lake has experienced unprecedented warming during the last century, and its surface waters are the warmest on record. That finding is important, the scientists write in the journal Nature Geoscience, because the warm surface waters likely will affect fish stocks upon which millions of people in the region depend.

The team took core samples from the lakebed that laid out a 1,500-year history of the lake’s surface temperature. The data showed the lake’s surface temperature, 26 degrees Celsius (78.8°F), last measured in 2003, is the warmest the lake has been for a millennium and a half. The team also documented that Lake Tanganyika experienced its biggest temperature change in the 20th century, which has affected its unique ecosystem that relies upon the natural conveyance of nutrients from the depths to jumpstart the food chain upon which the fish survive.

“Our data show a consistent relationship between lake surface temperature and productivity (such as fish stocks),” said Jessica Tierney, a Brown graduate student who this spring earned her Ph.D. and is the paper’s lead author. “As the lake gets warmer, we expect productivity to decline, and we expect that it will affect the [fishing] industry.”

The research grew out of two coring expeditions sponsored by the Nyanza Project in 2001 and 2004. Cores were taken by Andrew Cohen, professor of geological sciences at the University of Arizona and director of the Nyanza project, and James Russell, professor of geological sciences at Brown, who is also Tierney’s adviser.

Lake Tanganyika:
Lake Tanganyika

Lake Tanganyika is bordered by Burundi, the Democratic Republic of Congo, Tanzania, and Zambia — four of the poorest countries in the world, according to the United Nations Human Development Index. An estimated 10 million people live near the lake, and they depend upon it for drinking water and for food. Fishing is a crucial component for the region’s diet and livelihood: Up to 200,000 tons of sardines and four other fish species are harvested annually from Lake Tanganyika, a haul that makes up a significant portion of local residents’ diets, according to a 2001 report by the Lake Tanganyika Biodiversity Project.

Lake Tanganyika, one of the richest freshwater ecosystems in the world, is divided into two general levels. Most of the animal species live in the upper 100 meters, including the valuable sardines. Below that, the lake holds less and less oxygen, and at certain depths, it is anoxic, meaning it has no oxygen at all. What this all means is the lake is highly stratified and depends on wind to churn the waters and send nutrients from the depths toward the surface as food for algae, which supports the entire food web of the lake. But as Lake Tanganyika warms, the mixing of waters is lessened, the scientists find, meaning less nutrients are funneled from the depths toward the surface. Worse, more warming at the surface magnifies the difference in density between the two levels; even more wind is needed to churn the waters enough to ferry the nutrients toward the fish-dwelling upper layer.

: Jessica Tierney
Jessica Tierney

The researchers’ data show that during the last 1,500 years, intervals of prolonged warming and cooling are linked with low and high algal productivity, respectively, indicating a clear link between past temperature changes and biological productivity in the lake.

“The people throughout southcentral Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” noted Cohen, an author on the paper. “This resource is likely threatened by the lake’s unprecedented warming since the late 19th century and the associated loss of lake productivity.”

Climate change models show a general warming in the region, which, if accurate, would cause even greater warming of the Lake Tanganyika’s surface waters and more stratification in the lake as a whole. “So, as you move forward, you can imagine that density gradient increasing,” said Russell, an author on the paper.

Some researchers have posited that the declining fish stocks in Lake Tanganyika can be attributed mainly to overfishing, and Tierney and Russell say that may be a reason. But they note that the warming in the lake, and the lessened mixing of critical nutrients is exacerbating the stocks’ decline, if not causing it in the first place. “It’s almost impossible for it not to,” Russell said.

Other authors on the paper are Brown graduates Marc Mayes and Natacha Meyer; Christopher Johnson at the University of California, Los Angeles; and Peter Swarzenski, with the United States Geological Survey. The National Science Foundation and the Nyanza Project funded the research.

=======================================

Here is the University of Arizona version

=======================================

Twentieth-Century Warming in Lake Tanganyika is Unprecedented

Lake Tanganyika Sailing
An artisanal fisher sails on Lake Tanganyika. (Photo credit: Andrew S. Cohen)
Cohen
UA geosciences professor Andrew S. Cohen (in the pink shirt) and students in the UA’s Nyanza Project look at a sediment core from the bottom of Lake Tanganyika, the world’s second deepest lake. (Photo credit: Laura Wetter)

Warming in the last century threatens one of Africa’s largest inland fisheries.

By Mari N. Jensen, College of Science, May 17, 2010

Lake Tanganyika’s surface waters are warmer than at any time in the previous 1,500 years, a University of Arizona researcher and his colleagues report online in Nature Geoscience.

The rise in temperature during the 20th century is driving a decline in the productivity of the lake, which hosts the second-largest inland fishery in Africa.

“People throughout south-central Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” said study co-author Andrew S. Cohen, a UA professor of geosciences. “This resource is likely threatened by the lake’s unprecedented warming since the late 19th century and the associated loss of lake productivity.”

This is the first detailed record of temperature and its impacts on a tropical African ecosystem that allows scientists to compare the last 100 years with the previous 1,400 years, Cohen said.

The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.

“We’ve got a global phenomenon driving something local that has a huge potential impact on the people that live in the region and on the animals that live in the lake,” he said.

The annual catch of the Lake Tanganyika fishery is estimated at about 198,000 tons per year, more than 20 times greater than the U.S. commercial fishery in the Great Lakes, he said. The nations of Burundi, Tanzania, Zambia and the Democratic Republic of Congo border the lake, which is the longest lake in the world and the second deepest.

The surface waters of Lake Tanganyika are the most biologically productive part of the lake. For the 1,400 years before 1900, those waters were no warmer than 75.7 F (24.3 degrees C). Since 1900, the lake’s surface waters warmed 3 degrees F, reaching 78.8 degrees F (26 degrees C) in 2003, the date of the researchers’ last measurement.

The researchers used sediment cores from the lake bed to reconstruct the 1,500-year history of the lake. The scientists analyzed the cores for chemicals produced by microbes and left in the sediments to determine the lake’s past temperature and productivity.

Because sediment is deposited in the lake in annual layers, the cores provide a detailed record of Lake Tanganyika’s past temperatures and productivity and of the regional wildfires.

The instrument record of lake temperatures from the 20th century agrees with the temperature analyses from the cores, Cohen said.

The cores were extracted as part of the UA’s Nyanza Project, a research training program that brought together U.S. and African scientists and students to study tropical lakes. The National Science Foundation funded the project.

“A big part of our mandate for the Nyanza Project was looking at the interconnectivity between climate, human activity, resources and biodiversity,” said Cohen, who directed the multi-year project.

Lake Tanganyika and similar tropical lakes are divided into two general levels. Most of the fish and other organisms live in the upper 300 feet (about 100 meters). At depths below that, the lake waters contain less and less oxygen. Below approximately 600 feet, the lake water, although nutrient-rich, has no oxygen and fish cannot live there.

During the region’s windy season, the winds make the lake’s surface waters slosh back and forth, mixing some of the deep water with the upper layers. This annual mixing resupplies the lake’s food web with nutrients and drives the lake’s productivity cycle, Cohen said.

However, as Lake Tanganyika warms, the upper waters of the lake become less dense. Therefore, stronger winds are required to churn the lake waters enough to mix the deeper waters with the upper layer. As a result, the upper layers of the lake are becoming increasingly nutrient-poor, reducing the lake’s productivity.

In addition, warmer water contains less dissolved oxygen, reducing the quality of the habitat for some fish species.

Other lakes in Africa are showing similar effects to those the team found in Lake Tanganyika, he said.

The finding has implications for lakes in more temperate climates.

“Increasingly, lakes in the U.S. are warming and they’re behaving more like these African lakes,” Cohen said. “There’s a potential for learning a lot about where we’re going by seeing where those lakes already are.”

The team’s article, “Late twentieth-century warming in Lake Tanganyika unprecedented since AD 500,” will be published in the June issue of Nature Geoscience.

Cohen’s co-authors on the paper are first author Jessica E. Tierney of Brown University in Providence, R.I.; Marc T. Mayes, Natacha Meyer and James M. Russell, also at Brown University; Christopher Johnson, a former University of Arizona student now at the University of California, Los Angeles; and Peter W. Swarzenski of the U.S. Geological Survey in Santa Cruz, Calif. The National Science Foundation funded the research.

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May 18, 2010 7:12 pm

And of Course Greenland is melting away — see CBC…
http://www.cbc.ca/technology/story/2010/05/18/greenland-land-rising.html
The GPS determined that the increases in land elevation began in the mid-1990s.
Clever GPS…

Henry chance
May 18, 2010 7:23 pm

Can the authors come over to this leading science blog and explain this?
They wrote a story but offer no actual facts?

Henry chance
May 18, 2010 7:28 pm

This story is getting fishy. What are they thinking? The temps last measured in 2003. There is no excuse for this. If a real team went out there and measured it today and found it had dropped, what would they say?
The other fish tale portion is the catch doesn’t really prove much. If the fishing methods are not identical, she has no way of proving there are more or less sardines packed in water.

Al Gored
May 18, 2010 7:36 pm

OK. Let’s pretend the results are accurate, to 2003, and that all the carefully ignored other factors don’t matter. Why was it as warm in 500 A.D.?

Derek B
May 18, 2010 7:39 pm

What the … is indunation? Covering with dunes? Or inundation perhaps?
Reply: Fixed. ~ ctm

David44
May 18, 2010 7:50 pm

Picking nits:
“Lake Tanganyika is the second largest lake in the world for fresh water, …”
Lake Tanganyika is the second largest lake in Africa, not the world. It is the sixth largest (freshwater) lake in the world by area.
Reply: Second or third in the world by volume. I’ll amend for clarity. ~ ctm

Ed Caryl
May 18, 2010 7:50 pm

I wonder if they bothered to measure the thickness of the annual layers in the cores? Increased turbidity would increase the annual layers, right? But that would disprove their theory, wouldn’t it? Very bad science!

jorgekafkazar
May 18, 2010 7:57 pm

“…increasing the albedo to absorb more sunlight on the lake …”
Uh, high albedos reflect more light. You mean increasing the absorptivity.
Reply: Fixed, but in a different way. ~ ctm

rbateman
May 18, 2010 7:58 pm

Another ‘what else could it be’ warming story.
Where’s the data?
Has anyone checked on rift action, since it is in Africa’s Rift Zone?

May 18, 2010 7:59 pm

OK, so Lake Tangyanika stretches from 3 degrees S latitude to 8 degrees S latitude. turning to GISS for the latitude band 0-24S, the temperature change from 1900 to 2003 is 0.5 degrees C. Researchers claim the lake has warmed 3 degrees F. Why is the lake experiencing a temperature anomaly 3 times that of the rest of the planet at that latitude? And what warms it? Certainly not CO2, since LW from CO2 only penetrates a millimeter or less of water and just evaporates back up into the atmosphere… Oh yeah, there were those posts on WUWT about decreased storm intensity in opposition to what the climate models predicted… Oh yeah, the article talks about storm activity sloshing the lake around and bringing water up from the bottom…. cold water…. less storms…. less mixing…. I know I’m really close to figuring this out…. just can’t quite put my finger on it…. less storms, less cold water coming to top, almost got it…. GOT IT! The LW is heating up the boats on the lake which in turn heat the lake! Itz AGW! And global warming reduces storm activity which makes it even worse because the boats can spend more time on the lake! Itz a feedback loop!

dp
May 18, 2010 8:05 pm

Fertilizer.

pat
May 18, 2010 8:06 pm

O/T but this waste of taxpayers’ money has received very little media attention since it sank last Saturday:
wikipedia: Oceanlinx
Oceanlinx is a Wave Energy Converter device , that is a device which uses wave energy and converts it into electrical energy operating on the oscillating water column principle. The Oceanlinx was developed in Australia. The technology has developed greatly in the past ten years thanks to the large amount of international funds it has received.
http://en.wikipedia.org/wiki/Oceanlinx
wiki also lists all the funding, plus the countries and US States that are spending on the technology.
the following are from Illawarra Mercury, Australia:
15 May: $5m Port Kembla wave generator wrecked
It will be a blow to Oceanlinx, which had been keen to prove the project was commercially viable.
The wave-to-energy barge, known as the Mk3, was at the forefront of marine renewable technology and has operated for four years.
Launched at a ceremony on March 29 by Federal Environment Minister Peter Garrett, it is feeding power into the Integral Energy grid.
The mishap caused a 45-minute power outage to nearby areas
http://www.illawarramercury.com.au/news/local/news/general/5m-port-kembla-wave-generator-wrecked/1830582.aspx
17 May: Port Kembla wave generator on sea floor
Throsby MP Jennie George said the sinking of the prototype was devastating news.
“There had been mooring problems with earlier models and the company was confident these had been ironed out,” Ms George said.
“But companies and governments needs to keep persevering … renewable energy is an important part of the energy mix in reducing carbon emissions in the future. I’m sure Oceanlinx will overcome this setback.”
http://www.illawarramercury.com.au/news/local/news/general/port-kembla-wave-generator-on-sea-floor/1831275.aspx
19 May: Barge’s watery grave
Hopes of saving the ill-fated Oceanlinx barge were dashed yesterday after it was discovered smashed to 40 pieces and scattered across the seabed at Port Kembla.
A dive team inspecting the 170-tonne wreck spent hours searching for the damaged metal remnants, combing through masses of thick seaweed at the base of the eastern break wall…
The barge was at the forefront of renewable marine technology and had fed power back to the Integral Energy grid since March this year..
Last year Oceanlinx won a $3 million Climate Ready federal grant to help develop the device, all of which had been allocated.
http://www.illawarramercury.com.au/news/local/news/general/bargeswatery-grave/1834461.aspx

Geoff Sherrington
May 18, 2010 8:07 pm

I defy any scientist to measure the temperature of the water at 78.8 deg F with uncerainty that allows the digit after the decimal. I’d put the error, unashamedly subjectively, at about +/- 5 deg F. That’s about what I feel when I take a dip in the pool. For L. Tanganyika, how deep, sun angle, cloud or not, how calm, day or night, season, influence of Rift valley volcanism, mixing, oxidation/reduction of biomass variations with nutrient input/output … Many, many factors.

May 18, 2010 8:13 pm

Several publications show that fish productivity increases with temperature, see e.g. the graph on page 61 and several others which follow (including sardines that this study mentions):
http://www.klimarealistene.com/09VaageV8R.pdf
They could have measured fish scales in the sediments as these authors did for a more direct indicator of fish productivity rather than using “chemicals produced by microbes” and apparently didn’t consider that the lake may be “over-fished” now compared to the last 1500 years.

May 18, 2010 8:17 pm
Eric Gisin
May 18, 2010 8:28 pm

200,000 tons of fish per year? That’s 2000 rail cars!

May 18, 2010 8:30 pm

The results stretching back to 500AD are essentially based on interpretation of core from ONE borehole.

INGSOC
May 18, 2010 8:40 pm

Perhaps a look back at the doomsday claims made by the USGS for a 100 year wasteland in the wake of St Helens eruption would show some similarities. Today it is a thriving system that shows little sign of anything having occurred. Acid rain was going to reduce everything to a gooey slop, but that never happened either. My favorite, Killer Bees, were going to mercilessly attack women and small children but that too didn’t pan out. Now they claim lakes are heating out of control due to a combination of acidic killer bees with volcanic temperament that will kill us all if we don’t run about on bent knees wailing about our terrible ways and go back to living in caves.
What a load of horse pucky!

Tom Jones
May 18, 2010 8:43 pm

It would seem like the temperature gradient due to solar heating due to increase turbidity is going to be very different than the temperature gradient due to warming of the atmosphere. There is no mention of trying to measure the thermal gradient at all.

May 18, 2010 8:43 pm

In one interview I read the paper author told the interviewer that several warming and cooling cycles were seen in the sediment data but this one is warmer then the others. I am not a limnologist but the link to AGW is weak to non existent at best. The major concern in this and other lakes is overfishing. If the water temperature effects fish productivity and it does, as far as I know, the sustainable yields will change and that is not good if you need that food source. That said, as others pointed out above many things influence yields besides temperature. A complex situation with unfortunately not simple answers.

Craig Goodrich
May 18, 2010 8:43 pm

Thanks for this illuminating article. But it leaves me a little confused.
Was it that a thousand years ago, when according to African stalagmites the temperature was more than 1 deg C warmer, the lake was nonexistent?
Or was it that the lake was there, but there were no fish in it?
Or have all the fish evolved in the last 8000 years, since the end of the last glaciation, and they’re having trouble with the recent cooling?
Please explain.
Sincerely, Confused

May 18, 2010 8:51 pm

No surprise that it is published in Nature. Good science articles should always address and discuss the confounding factors. But it seems that Nature encourages articles on Global Warming that avoids discussing confounding variables. It is degrading the scientific process. I have seen it in so many “blame global warming for changes” in butterflies, amphibians, etc . Climate-gate and Josh Demming exposed the gatekeeper effect that restricted articles that contradicted AGW. But I think even worse is that Nature puts out articles with very weak evidence that is often contradicted by other good scientific papers about how AGW is disrupting nature, like Pounds’ paper claiming 99% certainty a la IPCC that AGW caused the frog extinctions. Then those papers and ideas go viral, which I suspect is their strategy.

Fitzy
May 18, 2010 8:56 pm

/rant on
Ok, my pet hate, wheres the preceding….’We estimate that….’ or the polite, ‘the data appears to show that…’, i’ll even settle for ‘We interpret the data as…’
Nah.
Nada, thanks to the French business school of management, no uncertainty is permisable. BUT! uncertainty is the foundation of science, it prompts a questioning mind in action. How many poorly reported stories must we endure? Always straight to a statement of fact,…”Lake Tanganyika’s surface waters are warmer than at any time in the previous 1,500 years.” Thanks DR WHO, must be handy, time travellin’ an all.
A proxy ain’t mecury observed and logged, its a “what if”, underlined with a “perhaps” and punctuated with a “maybe.”
To illustrate:
“What if” the AGW-biased Tanganyika research is !#$@*&%$ wrong, and “Perhaps” there is another [Self-Snip]ing answer, “maybe” you could do some actual science that doesn’t rely on a barney the dinosaur level of comprehension.
/rant off.

Rich Matarese
May 18, 2010 8:56 pm


For general information, the report is published in the form of a letter (Tierney, Mayes, Meyer, et al, “Late-twentieth-century warming in Lake Tanganyika unprecedented since AD 500”). Links I have noted are:
1) Brown University press release at http://tinyurl.com/3y789dv
2) Online journal citation at http://tinyurl.com/37gm7wh (full access available only to subscribers of Nature Geoscience)
3) Supplemental information (in PDF) at http://tinyurl.com/27tfgx3 (fully accessible at the time of this posting)
The usual warmist crap is being spouted and supported by the True Believers online at The Independent (UK) regarding this study.
Whenever I encounter the AGW cabal chicken-dancing like this, I am minded of my youngest granddaughter (now a lordly five years of age) some several years ago falling upon an Easter egg in the back yard and yelping self-righteously to her older brother that here was proof positive that the Easter Bunny really does exist.

Pat Moffitt
May 18, 2010 9:13 pm

The real evil of climate change is the systematic hostage taking of all environmental problems. We can solve no problem if the answer is not climate change and as such we solve few problems. This fishery feeds millions of dependent people- to put climate change as the primary driver is at best reckless.
We have an estimate from the 2003 Nature article that the lake’s anchovy biomass is 300,000 metric tons and the current research saying the harvest is 200,000 metric tons. Overfishing? How accurate are the fishery records? The 2003 Nature study says we don’t know the true harvest:
“But the data on the lake is poor and no one really even knows how many people are fishing on the lake. Half of the Tanganyika shore belongs to the Democratic Republic of the Congo, but a long-standing civil war there means fishing records are hard to get.”
A 1991 study by Coulter found other fishery statistic problems:
“The lack of a comprehensive study compounds the continuing problem created
by the frequent confusion between their ‘true’ abundance and their seasonal/annual catchability, which strongly depends on their feeding/spawning habits and impacted on by fishing strategies/efficiencies .”
The comparisons made to the US Great lakes commercial catch is disingenuous at best. The US fishery collapsed some 60 years ago from overfishing. The Great Lakes are now managed as a recreational fishery with a very limited commercial take. The researchers make the statement about Lake Tanganyika’s relatively higher productivity (20X catch)- but fail to appreciate the irony of the Great Lakes being much colder.

pat
May 18, 2010 9:14 pm

one to watch, tho i haven’t checked the reader’s comment on accuweather:
19 May: UK Daily Mail: Blazing in, the 80f weekend: But we’ll soon be cooling down again
(Met Office forecaster Helen Chivers) ‘A temperature of 25c (77f) is possible on Friday and temperatures might reach 26c (79f) on Friday or Saturday,’ Miss Chivers said…
COMMENT BY READER: AccuWeather gives a maximum of 16C today with rain at 0800 and again at 1100 in the North West of England – and a MAXIMUM temperature of 12C on Sunday.
What a shame the Met Office cannot agree on the forecasts projected by AccuWeather and others of that ilk.
http://www.dailymail.co.uk/news/article-1279270/Get-ready-long-barbecue-summer-temperatures-forecast-hit-39C.html#comments

George Turner
May 18, 2010 9:18 pm

Even if the claims are true, which they aren’t, wouldn’t it be cheaper to buy each of the 10 million local residents their own restaurant chain than implode the economies of the entire industrialized world?

Rich Matarese
May 18, 2010 9:23 pm


@ Tom Jones, regarding temperature gradient findings (or the lack thereof), not having full online access to Nature Geoscience – and certainly unwilling to pay $18 for such access to this single letter – I cannot say for sure that the perpetrators of this study harvested any information on water temperatures at varying levels or other sites in Lake Tanganyika.
Who knows? Perhaps such information is being reserved for later baloney-slicing. Those of us who have published on any sort of research are familiar with the need to get as many entries in our curricula vitae as possible out of the expenditures we oversee.
But speaking from the perspective of a trained biologist who spent some rather miserable time on the water decades ago dunking a Nansen bottle and recording temperatures at varying depths by way of a thermocouple attached to the gadget, I’m aware of the fact that whenever you drop any weight on a line into a body of fluid, you can sure as hell do a bit of rough-and-ready bathythermography.
Measuring nothing but surface temperatures offers no insight into the total heat being accumulated by the waters of Lake Tanganyika, not so? Moreover, if surface water turbidity – as the result of agriculture-promoted sediment run-off from the tributaries’ drainage areas – is increasing solar heat absorption and leading to increased stratification (meaning that there is less updwelling of colder, nutrient-rich bottom waters), there is a more immediate, much more powerful causative mechanism that must be considered and ruled out before anthropogenic global warming is trumpeted.

Rich Matarese
May 18, 2010 9:40 pm


Addendum. If there’s anyone reading here who does have access to Nature Geoscience, could there be some examination of this letter to see whether or not the investigators performed nephelometric evaluations of surface waters and samples taken at depths within the range at which freshwater phytoplankton might customarily be expected to populate Lake Tanganyika?
I would think that some such method – to assess the degree of reduction in the intensity of incident light after passing sequentially through waters ranging down from the surface as the result of turbidity – together with analyses of the chemical compositions of these samples, the microflora contained therein, and determination of the nature and levels of such particulates as might be suspended in the water at these shallow and easily accessed depths would be part of any examination of Lake Tanganyika as a physical phenomenon.
Or couldn’t these clowns get a biologist or two to come along with them?

el gordo
May 18, 2010 9:50 pm

Al Gored 7:36 pm
It may have something to do with the 1500 year climate cycle they found in the ice cores. Perhaps the Dark Ages that followed wasn’t really as bad as itz rumored to have been.

barefootgirl
May 18, 2010 9:50 pm

Anyone actually read the paper? I wouldn’t just rely on the media coverage. From the first press release shown here, it seems they are mostly talking about fluctuation in productivity linked to temperature. In the second, they mention a link to GHGs. What does the actual paper say? I think until you actually READ the paper rather than these press releases you really don’t have anything to say.

Gary
May 18, 2010 9:52 pm

Uhhhh……. isn’t Lake Tanganyika located over a “mantle plume” which is thought to heat the crust, causing a lot of the geological activity in this portion of Africa?

Pat Moffitt
May 18, 2010 9:58 pm

Anyone know how these researchers used core sediment samples to determine a 1.7C increase in SURFACE temperatures over a 1400 year period from a lake with mean depth of 570 meters? They also say the rapid warming started in the late 19th century- can we say end of LIA?

David L
May 18, 2010 9:59 pm

So why isn’t my inground pool 3 degrees warmer? I’ve been recording the temperature daily every summer. Last summer it was the coldest of the prior five years. This year I haven’t even opened it yet. It’s been far too cold. Why does global warming only seem to occur in far away places like the arctic, central Africa, or the top of the Himalayas, but not here in Philadelphia?

Sleepalot
May 18, 2010 9:59 pm

An article from Nat. Geog. 2000.
“Allen compared Baikal to the U.S.-Canadian Great Lakes, now believed on
the rebound after years of abuse. As a worst-case outcome, she cited Lake Tanganyika which, unlike teeming Baikal, is all but lifeless. ”
http://news.nationalgeographic.com/news/2000/12/1201_russianlake.html
Is this “Schrodinger’s lake” – dead one minute, and alive the next?

James Sexton
May 18, 2010 10:01 pm

“anoxic, meaning it has no oxygen at all”……….uhmm, at the risk of displaying my ignorance…..yet again, how does H2O contain no O?
Reply: Anoxic means depleted of dissolved Oxygen. ~ ctm

DCC
May 18, 2010 10:05 pm

The Brown University geology department has been doing some very PC “research” lately. I hope they recover.

Lawrie Ayres
May 18, 2010 10:07 pm

I too am depressed by the constant release of half baked papers offering no more than an alarmist headline. My question is where are the papers/letters/statements refuting this garbage? We have ben told often that geologists by and large don’t buy the AGW line yet we rarely hear or see such statements.
Just today the president of the Australian Council of Trade Unions is calling for the creation of 3.6 million green jobs over the next two decades. Maybe she hasn’t heard of the green economies of Spain or California and the associated deterioration in those economies. The warmers, generally leftists, are hell bent on curbing CO2 and are totally ignorant of alternative explanations for perceived climate change. The danger of Trading schemes and hairbrained green technologies is alive and well.

Rich Matarese
May 18, 2010 10:11 pm

@ barefootgirl, see http://tinyurl.com/37gm7wh for online access to Nature Geoscience‘s early promulgation of this letter. If you want full access, they expect you either to be a subscriber or to cough up eighteen bucks.
Got your credit card handy?
@ Gary, on the possibility of an underlying mantle plume or similar geothermal factor which might conceivably account for any heating of the waters of Lake Tanganyika, I don’t believe that any mention has been made. Warmist True Believers I’ve thus far encountered elsewhere causelessly dismiss this possibility.
Frankly, I would dismiss it, too. To the best of my limited understanding, this study has incorporated precisely no bathythermographic assessment (easy as that would have been to conduct as part of the geologists’ sediment core sampling activity, you’d think) and therefore not even the simple consideration of the heat content increases required to raise the temperature of Lake Tanganyika’s contents as a whole to any reliably mensurable extent.
I’m willing to go (for the nonce) with the notion that the surface waters may have increased in temperature, and that there has been the induction of a degree of stratification hitherto not observed in the lake. What does this tell, however, about the temperature of the waters deeper down? Have the investigators in this study even bothered to consider that question? Present deponent answereth not.
Without some idea of temperature increases (if any) within the depths of Lake Tanganyika, speculations about geothermal contributions are (to quote a line from Blazing Saddles) “…just jerking off.”

May 18, 2010 10:41 pm

They claim that the core data agree with the instrument data. What instrument data? I cannot find any instrument data near Lake Tanganyika. There are no weather station with a continous record near the lake, even if you stretch the meaning of “near” to be rather far away. Most that existed seem to have close. At least they don’t report data anymore. For example, the weather station in Harare stopped reporting in 1991. Before that, the temperature had dropped slightly compared to 1915.

Al Gore's Holy Hologram
May 18, 2010 10:53 pm

Decoded : stop African development. Keep blacks poor. Better to be a noble savage. Keep all energy resources for the superpowers.

Georgegr
May 18, 2010 11:03 pm

It is well known that fertilizers used in modern agriculture leaking into lakes cause algeae to bloom, in turn the algeae will deplet the oxygen in the lake. Very common problem in lakes surrounded by farmland and/or unfiltered sewers.

zeta
May 18, 2010 11:08 pm

A slight warming in the surface layers of a lake that represents some promilles of the earths area is a proof of co2-induced global warming ? Uh, ok.

Brian S
May 18, 2010 11:16 pm

Meanwhile, just a couple of days slow train ride down the track “Bankruptcy threat as SA farmers produce a mountain of maize” (Business Day 18/5/2010). “South African maize farmers, bouyed by unexpectedly good rains,,,,,,,,are preparing to reap their biggest crop in 28 years. The reward for their success may be bankruptcy …………Overplanting, after the national meteorological agency warned of a drought that did not materialise also helped cause this year’s bumper harvest.”
It seems we are likely to have a surplus of 6 million tons of grain, with no market for it. I don’t know but would hazard a guess that the drought scare was caused by global warming and the good rains were the true result of global warming.
At least there is no need for the ’10 million people living near the lake’ to starve – their governments can buy them half a ton each and we will still have a surplus. (But governments and greenies don’t think that way, do they?)

Sleepalot
May 18, 2010 11:29 pm

This any good?
“Hydrothermal vents in Lake Tanganyika, East African, Rift system”
http://geology.geoscienceworld.org/cgi/content/abstract/21/6/499

Warrick
May 18, 2010 11:48 pm

Sardines in fresh water? I suspect they mean small tilapia (Sarotheradon species, or cichlids).

wayne
May 18, 2010 11:50 pm

… reaching 78.8 degrees F (26 degrees C) in 2003,
the date of the researchers’ last measurement. …
Breaking news…. on seven year old data,
nothing to see here, move on.

LightRain
May 19, 2010 12:35 am

1500 years ago there were probably 10,000 people living there and they didn’t cut down the forest to do their cooking. This is a different sort of UHI.

Berndt Koch
May 19, 2010 12:37 am

Lake Tanganyika is approx 3,000,000 years old, the sample of derived proxy temperature from sediment record is 1,500 years.. thats 0.05% of the lifespan of the lake.. and it’s ‘unprecedented’ ?? so we can discount the other 99.95% of it’s lifespan?

Tony Hansen
May 19, 2010 12:54 am

They did how many cores for a lake approx. 32,000 sq k in area?
(Magic boremometer perhaps).

James Atwell
May 19, 2010 1:04 am

95% of the east African natural forest has been destroyed in recent times.
Now there is something that will impact on the local climate.

May 19, 2010 1:10 am

There is a strong possibility that the heating is GEOTHERMAL. Lake Tanganyika is estimated to be the second deepest in the world, at 1,470 metres (4,820 ft), after Lake Baikal in Siberia. Water is a good thermal conductor (convection), while surrounding ground is not. Secular magnetic changes 1950 -2000 show that there are geological movements in area of the East African rift valley.
http://www.vukcevic.talktalk.net/NFC4.htm

May 19, 2010 1:14 am

Damn, what is with the U of A? That’s where I got my BS degree.
They’re becoming an embarassment.
Hopefully the College of Engineering and Mines, where I studied, is not infected by the geosciences faculty (have they been moved to the Humnaities and Social Sciences College, along with all the long-haired, 60s retread profs, or what?).
Who’s responsible for writing these kooky press releases at the U of A?

May 19, 2010 1:23 am

I just sent an e-mail to the editors.

Bob Layson
May 19, 2010 1:29 am

Since the globe hasn’t seen much global warming these last ten years, major cities and airports excepted, alarmists must point to the supposed effects of such warming. After all, if we see the effects of warming then warming there must have been.

Ian E
May 19, 2010 2:03 am

‘People that are really very weird can get into sensitive positions and have tremendous impact on history.’ Al Gore.
Need I say more! [ Hat-tip to Tom Bradby who gives this quote in another context, http://blog.itv.com/news/tombradby/ ]

May 19, 2010 2:48 am

If you say it is caused by global warming or even that it may be & put any reference to other possibilities in the small print you get funding from (ultimately) the government.
If you say it is not evidence of global warming you don’t.
What is a passably honest scientist who thinks the phenomenon really deserves study to say?

HotRod
May 19, 2010 2:53 am

How nice that they give us a picture of Jessica Tierney rather than Andrew Cohen or James Russell – can’t think why. Yesterday I fell in love with the youngest British woman climber of Everest, Bonita Norris. http://www.bonitanorris.com/

Joe
May 19, 2010 3:47 am

It is more about grant money to the University to put out more educated idiots into the “PEER REVIEW” system.
What happened to the good honest here ‘s the data and this is what we did to come to our conclusions? Is there draught in the area? Less cloud cover affects more solar radiation and the replenishment of the lake through precipitaion. What were the water levels? How many measurements of surface water and where? shorelines would be much warmer compared to much deeper.

Paul Coppin
May 19, 2010 4:02 am

“barefootgirl says:
May 18, 2010 at 9:50 pm
Anyone actually read the paper? I wouldn’t just rely on the media coverage. From the first press release shown here, it seems they are mostly talking about fluctuation in productivity linked to temperature. In the second, they mention a link to GHGs. What does the actual paper say? I think until you actually READ the paper rather than these press releases you really don’t have anything to say.

First, welcome to WUWT- clearly, by your responses, you are new here and new to the new science reality.
Only those who have access, and who are capable will read the actual paper. The vast majority will see or hear only a twist on the press releases. The vast majority. For the same reason many here will not fork over $18 for the paper, neither will the media. They don’t need to- that’s what press releases are for. The vast majority of “journalists” will only appropriate the portions of the press releases that a) fit the space, b) fit the bias, c) fit the agenda. For a large part of the world readership, the actual content of the paper doesn’t matter; the science in it doesn’t matter. Even the truth of the science doesn’t matter.
All that is required of current science publication by branded institutions is that the paper be “peer-reviewed” by somebody who can advance the agenda. By the time the word gets out that the scientist wears no clothes, the press release has done its job. Scientists that allow these kinds of press releases to stand with their name on(in) them have abandoned their scientific credentials. The content of their papers is soon lost in the miasma of reports, citations, politics and spin. Modern science publication is coming as close to McLuhanism as any media can be. New PhDs need to be especially careful about allowing them themselves to be hijacked; the coming cleansing will sweep them up too.

May 19, 2010 4:14 am

Geoff Sherrington: You wrote a brief but pertinent comment on measurement error and the many and complex drivers of temperature in Lake Tanganyika. The AGW theory, with its own measurement errors and exclusion of other drivers, bears a family resemblance to this.
However did wider society allow science to spout this futurological drivel to us? When Captain Cook was sent to Tahiti to observe the transit of Venus, heads would have rolled if he’d reported, “Er, no, Venus didn’t turn up”. How red-faced would Oppenhiemer have been if the Manhattan project had resulted in a little clicking sound? Science used to (…in fairness, most of it still does…) depend on verifiable outcomes.
These latter-day Nostradamuses are getting away with murder, making careers out of predictions which can only be falsified after they can’t answer for their claptrap.

Rockdoc
May 19, 2010 4:29 am

Just a reminder that Lake Tanganiyka is part of the East African Rift system. It has arguably some of the highest heat flow measurements throughout Africa. As memory serves heat flow in these modern rifts where the continental crust is thinner is in the order of 110 mw/m2 as compared to more normal ranges of 20 – 30 mw/m2 in the cratoninc portion of Africa. In a few hundred million years I wouldn’t be surprised to see that everything east of the rift system was rafted out into the Indian Ocean.
Its active as the hydrothermal activity suggests.
Haven’t read the paper but I would hope someone who works for the USGS can separate out crustal heating from atmospheric heating.

Gail Combs
May 19, 2010 4:43 am

barefootgirl says:
May 18, 2010 at 9:50 pm
Anyone actually read the paper? I wouldn’t just rely on the media coverage. From the first press release shown here, it seems they are mostly talking about fluctuation in productivity linked to temperature. In the second, they mention a link to GHGs. What does the actual paper say? I think until you actually READ the paper rather than these press releases you really don’t have anything to say.
______________________________________________________________________
Fine, why don’t you spend the eighteen dollars for access and report back with the data they use to support their statements. I am out of work and broke so I can not.

H.R.
May 19, 2010 4:53 am

MarcH says:
May 18, 2010 at 8:30 pm
“The results stretching back to 500AD are essentially based on interpretation of core from ONE borehole.”
I’ll see your ‘one borehole’ and raise you ‘two trees’.

Steve from Rockwood
May 19, 2010 4:54 am

A study of a single lake in Africa cannot be linked to AGW. A more interesting study would have been to compare two lakes in different parts of the world where humans have had no local impact. Hmmm…

Richard111
May 19, 2010 5:01 am

“”Up to 200,000 tons of sardines and four other fish species are harvested annually from Lake Tanganyika, a haul that makes up a significant portion of local residents’ diets, according to a 2001 report by the Lake Tanganyika Biodiversity Project.””
And what was the annual harvest in 1901? How many “local residents” then?

May 19, 2010 5:02 am

The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.
The authors forgot — “The Team” is always capitalized…

pesadilla
May 19, 2010 5:35 am

The concept of climate change has evolved to the point where it no longer needs co2 in order to create havoc. It is now a phenomenon in its own right. (possibly like dark matter). The phrase is most useful in obtaining grants for scientific studies and is more than capable of generating large amounts of money in order to perpetuate itself. It even has its own laws like azimovs robotics laws.
1)all projects that confim its existance of agw will supported and funded generously and without question
2) Any new project which is intended to support the first law will also be funded.
2) Any project containing the words “green” “renewable” or “endangered” etc will be seriously considered, provided that their findings do not conflict with the other two laws

Pascvaks
May 19, 2010 5:48 am

“Unprecedented” – Without precedent.
“Precedent” – An act or instance that may be used as an example in dealing with subsequent similar instances.
Ergo – The use of the word “Unprecedented” is unscientific hogwash, it cannot be used without evidence of all subsequent instances being known. ‘All subsequent instances’ means a complete record back to the very beginning, in time, of the person, place or thing being studied.
Note – In the language of ‘New Age Psyence’ the use of the term “unprecedented” is called for whenever data suggests that something is (or might be) hotter, colder, wetter, drier, or whatever, today –or whenever– than it was yesterday –or whenever.
_________________
As noted by others, LOOK OUT FOR GREENLAND – the land is rising, the ice is melting, the weather is changing, the sky is falling. It’s “unprecedented”, really! (Well it IS if you’re a ‘Psyentist’.)
http://www.physorg.com/news193410777.html

Bruce Cobb
May 19, 2010 5:52 am

So then, it must be WTWT. The lakes are warming, or at least their surface layers are, and through the magical powers of CAGW/CC they are apparently warming much faster than the air itself is. These nitwits confuse and conflate actual localized environmental effects man has, e.g. pollution, deforestation, over-fishing, etc. with an overall warming of the atmosphere of perhaps .3C (since at least 1/2 of the temp increase measured is due to UHI, faulty placement of sensors, and station drop-out) since the end of the LIA. I guess they no longer actually teach at these “Universities”, but more indoctrinate. Very sad.

Charlie K
May 19, 2010 5:52 am

@ David L says: May 18, 2010 at 9:59 pm
Why does global warming only seem to occur in far away places like the arctic, central Africa, or the top of the Himalayas, but not here in Philadelphia?
Witnesses David, witnesses. When you’re mugging someone you don’t want too many people to see.
Though they have managed a pretty neat trick. To disprove AGW you must prove a negative, which if I remember correctly is a logical impossibility. And to top it off they make it as difficult as possible by doing research in the most remote places they can get to. Which means the average guy sitting in Philadelphia doesn’t have much of a chance to wander by and ask what they’re up to, much less verify what they’ve done.

starzmom
May 19, 2010 5:54 am

I am still trying to figure out how they came up with an absolute temperature value measured to the tenth of a degree from sediment cores. Seems as if that is simply not possible, and the range of error must be quite large. No mention of that however in the press release. Perhaps I will try to get the real article through the university library.

J.Hansford
May 19, 2010 6:03 am

It’s the turbidity changes that are affecting the temperature…. Not atmospheric temps… Certainly not CO2.

jack morrow
May 19, 2010 6:05 am

I am ashamed of people like this and I am tired of seeing my taxes used for things like this. Everyone who says they are out for grant money is right. What else can they do with their PhD but scam for grant money? They have never worked in a real job in their life. Academia, academia.
Forest clearing, population increases, over-fishing, fertilizer run off, and volcanic action could have all caused this. Anyone with any sense could see this and not just blame it on agw.

Juan El Afaguy
May 19, 2010 6:13 am

pesadilla says:
May 19, 2010 at 5:35 am
The concept of climate change has evolved to the point where it no longer needs co2 in order to create havoc. It is now a phenomenon in its own right. (possibly like dark matter). The phrase is most useful in obtaining grants for scientific studies and is more than capable of generating large amounts of money in order to perpetuate itself. It even has its own laws like azimovs robotics laws.
0)all projects that confim its existance of agw will supported and funded generously and without question
1) Any new project which is intended to support the first law will also be funded.
1) Any project containing the words “green” “renewable” or “endangered” etc will be seriously considered, provided that their findings do not conflict with the other two laws
Excellent! I have taken the liberty of renumbering the Laws of ACC (after messrs. Fibonacci, Wm. of Occ’m, & Codd and Date)

Editor
May 19, 2010 6:44 am

I don’t have a problem with them stating there have been changes in the lake which are anthropogenic induced. Clearly, man’s existence is going to have ‘some’ influence. Their jump to anthropogenic global warming being THE major cause is not acceptable however. They don’t know that.
Were all known natural influences identified, quantified, and segregated from data reflecting the change?
Were local and regional anthropogenic influences identified, quantified, and segregated from data reflecting the change?
The balance, after removing the above from the data, would be the starting point where ANY global warming ‘might’ potentially be responsible for changes identified.
So what did they really learn? It appears that the temperature of the water in Lake Tanganyika is not static, it changes over time. Changes in water temperature possibly has some affect the fish population. Both they could have learned in an 6th grade science class.
Can we get that monkey that does the hurricane predictions to have a look into Lake Tanganyika?

Bill Illis
May 19, 2010 6:45 am

Jessica Tierney published another paper in Science in 2008 using the same Tex86 temperature proxies on Lake Tanganyika (covering 60,000 years this time).
The data from 1,300 years ago shows the Lake temperature at 28C (versus 26C today) so one of the papers is wrong.
http://www.geo.arizona.edu/web/Cohen/pdf/83%20Tierney%20et%20al%202008.pdf
http://www.ncdc.noaa.gov/paleo/pubs/tierney2008/tierney2008.html
[One always has to check the actual data used in these studies because the news releases and the abstracts are rarely supported by the actual data presented in the papers].

Geoff Alder
May 19, 2010 7:05 am

Or maybe the lake has simply been fished out, just like most of the waters of this Planet.

North of 43 and south of 44
May 19, 2010 7:08 am

Rich Matarese says in part:
” … Whenever I encounter the AGW cabal chicken-dancing like this, I am minded of my youngest granddaughter (now a lordly five years of age) some several years ago falling upon an Easter egg in the back yard and yelping self-righteously to her older brother that here was proof positive that the Easter Bunny really does exist.”
Of course the Easter Bunny really does exist, you can even see it lay an egg on TV. I believe that it works for Cadbury. Peer reviewed evidence.

Nigel Harris
May 19, 2010 7:11 am

So, nobody is prepared to invest $18 and an hour or so to actually understand what these scientists are saying. Instead, we now know that, whatever it is that they’re actually saying, it can’t be true, because…
… they used an instrumental measurement from 2003, and “There is no excuse for this.” [Henry Chance]
… perhaps they didn’t bother to measure the thickness of the the annual layers in the cores, and this is “Very bad science!” [Ed Caryl, who clearly couldn’t be bothered to actually check that the allegation of incompetence that he made is correct]
… CO2 is incapable of warming more than the top millimeter of water [davidmhoffer]
… Fertilizer [DP]
… no scientist could possibly measure water temperature to closer than + / – 5 deg F [Geoff Sherrington]
… they didn’t measure fish scales and they didn’t consider over-fishing [Hockey Schtick]
… 200,000 tons of fish a year is an unbelievable claim [Eric Gisin]
… it’s all based on ONE borehole [MarcH]
… it’s a load of horse pucky [INGSOC]
… they didn’t mention measuring the thermal gradient [Tom Jones]
… the link to AGW is weak to non existent at best [Dennis Nikols, who is not a limnologist]
… it’s all part of Nature’s pro-AGW viral plot [Jim Steele]
… there’s no “actual science” here [Fitzy]
… the claims “aren’t true” [George Turner, who apparently needs no evidence or logical basis to make this claim]
… measuring only surface temperatures tells you nothing about total heat accumulation [Rich Matarese, who admits he has no idea whether or not they measured anything other than surface temperatures, or indeed, whether they make any claims about total heat accumulation, but calls the researchers “clowns” anyway]
… it’s all being caused by geothermal heating [Gary]
… it’s clearly impossible [implies Pat Moffit’s rhetorical question] to say anything about historical surface temperatures from core samples taken from the bottom of a lake
… David L’s pool in Philadelphia isn’t any warmer than it was 5 years ago
… there are no instrumental data records to calibrate the core data to [Lars Kamel]
… there’s no such thing as a fresh water sardine [Warrick]
… it’s 2003 data [Wayne]
… the lake is too old [Berndt Koch]
… the lake is too big [Tony Hansen]
… 95% of the forest has been destroyed [James Atwell]
… the globe isn’t warming [Bob Layson]
… a study of a single lake in Africa cannot be linked to AGW [even, presumably, if it is the second largest body of freshwater in the world, according Steve from Rockwood]
Geez, these “scientists” are just dumber than dumb. As well as being incompetent and corrupt. Why didn’t they think to come here first and find out all the real answers? Would have saved them all that heat and those flies in Africa.

May 19, 2010 7:12 am

The key claim is that warming will reduce fisheries on the lake: “The people throughout southcentral Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” I would argue that people in the area rely on fishing technology as much as the fish. Do they fish with nets thrown by hand? Advanced fishing boats? There is a nice YouTube video “Travel and fishing on lake Tanganyika” where you can see one fishing boat then others along the lake: http://www.youtube.com/watch?v=2KxEZR9-vGQ (with nice music). This is a stunningly beautiful place and should attract thousands then tens of thousands of tourists. How many billions of dollars are spent on sports fishing an diving each year? How many have been to Lake Tanganyika?
Infrastructure would develop to support tourists and funded by tourism and supporting the local economies.
Some visitors would be entrepreneurs and investors who would see opportunities in enhancing commercial fisheries. Maybe some fish farming. Maybe others would see potential in devising ways to enhance circulation of deep waters with surface waters to enhance fisheries.

Enneagram
May 19, 2010 7:12 am

“east African rift…”? The following image explains it all:
http://blue.utb.edu/paullgj/physci1417/Lectures/Continental_Rifting.JPG

Enneagram
May 19, 2010 7:15 am

So…vukcevic says:
May 19, 2010 at 1:10 am
There is a strong possibility that the heating is GEOTHERMAL.

IS RIGHT!
http://www.vukcevic.talktalk.net/NFC4.htm
BTW, what about Yellowstone?

Enneagram
May 19, 2010 7:19 am

..Though there are some questions: What did cause those GMF changes?, if magnetism, as it is, caused by an electric current, could it be possible that local heating is a kind of induction heating?

Itemten
May 19, 2010 7:28 am

As an ocean engineer I worked on a project regarding methane harvesting in Lake Kivu (a nearby African rift valley lake). Most of the lakebed was made up of siliceous ooze (greater than 30% organic/animal derived material in the sediment) which housed methane and H2S deposits. This layer of sediment has a layer depth that varies from 15 to 100 meters (estimated). The ooze effervesces when brought to the surface and is kept just below the surface, to release the gases in the water, before being brought onboard for examination. I have heard, but have not entirely verified, that the other rift valley lakes have similar bottom conditions. Bearing this in mind I wonder exactly how they are pinpointing temperature data from unstable/disturbed core samples.
Note that the only core samples on record for Kivu are from gravity cores which can only retrieve a few meters (in most cases 4 meters) worth of sediment, I will have to check if Tanganyika studies used different devices. Woods Hole has done a great deal of surveying in the rift valley lakes and their records are online for verification.
My curiosity is getting the best of me yet I am hesitant to subscribe to a journal of which I am only interested in a single article. Does anybody know exactly how they are retrieving this information?

1DandyTroll
May 19, 2010 7:43 am

So for years, even decades, folks have spent enormous amount of energy, time, and money to try to solve the ever increasing pollution problem in Africa, and for lakes and river especially, and some hobnob greenie is now shouting global warming as the problem?
So all the waste being dumped into the lake, chemical waste included, and all the unmanaged crap going into the lake from the shore from industries and cities, and the lake having been used as such for decades and decades, is not the cause of the problem anymore because now AGW is?
Those greenies will stop at nothing to try and apparently destroy everything for the sake of upholding a pseudo scientific hypothesis. Their intentions be damned.

Cardin Drake
May 19, 2010 7:43 am

A few questions come to mind:
1) Did the air temperature in the region increase?
2) Was it enough to cause the alleged temperature rise in the lake? (Which still leaves the question of did the air temp cause the lake temp to rise or vice-versa?)
3) I would think the primary mechanism for heating lake (or ocean water) is direct absorption of sunlight. If the lake (or ocean) has a rising temperature, isn’t that mostly evidence of decreased cloudiness? This would tend to support those who say that solar cycle is responsible for the current global warming.
I can’t believe how shallow these types of articles are.

Dave Springer
May 19, 2010 8:03 am

Sixth largest lake in the world by surface area and second largest by volume, bordered by four countries, ten million people living near it, and fish harvest twenty times that of the US Great Lakes… and NO ONE has recorded the surface temperature since 2003? I find that unbelievable. All serious fishing boats, and surely there are some serious fishing boats even in that very poor region of the world, have GPS, sonar w/fish finder, and water temperature instruments. You can buy a combo unit with all those instruments for about $200. I live on the shore of a 20,000 acre impounded lake with an average depth of about 100 feet and have those instruments even in my recreational boat. The lake authority continually monitors the water temperature gradient at the dam down to a depth of 200 feet. Lake Tanganyika must have fishermen who see the surface temperature a thousand times a day every day of the year. Surely many fishing boats keep a log with the daily temperature readings in it.
What this sounds like, if we can believe that the surface temperature has changed significantly in recent years which seems to be a matter of great doubt given the authors’ most recent past measurement is seven years ago, is a change in the amount of water exchange in the deep and shallow layers. The lake I’m on is stratified by temperature. Annually the surface layer in the winter becomes colder than the bottom layer and the layers exchange. The low oxygen bottom layer has a bad odor and we know when the exchange occurs because we can smell it when it happens. In Lake Tanganyika there is no such annual exchange as it’s in the tropics and the surface never becomes colder than the bottom. Unless there is some source of bottom heating the paper would appear to be wrong about nutrient upwelling from the bottom. If such an exchange is actually happening then there’s a source of heat underneath the lake driving it. If there’s a source of heat underneath the lake then it must be identified, measured, and monitered before any conclusions can be reached about what’s happening. The surface warming by 3 degrees F due to the average air temperature over the lake warming by 1 degree is patently absurd.

Bruce
May 19, 2010 8:19 am

Dear Barefooted girl et al.,
I get the Nature Geosciences journal for free (uni.), so I was able to actually read the thing. It is not possible to export the full text PDF (legally) to here, but a link to the abstract MIGHT work for public parties (maybe not?):
http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo865.html
ELSE, you could ask the corresponding author for a PDF:
Jessica_Tierney@brown.edu
The article is only 4 pages long, well-written, but the proxies used have limits. Proxies used include the TEX86 (temp.) proxy, the weight per cent of biogenic silica and charcoal abundance (fire history). I am surprised that they did not use van Geel style NPPS (actual algal microfossils) to, but the report is a short one, and probably does not reflect the full effort. Still, one would like actual algal species ID’s to reconstruct eutrophication condfitions. I know next to nothing about TEX86, but I am assuming the this proxy (being useful in oceans and LARGE lakes only) MIGHT be sensitive to increased turbidity due to major human impacts in the hydrosphere, as suggested by the WUWT author. I have done diatom studies on Holocene age pollen cores from Texas estuaries, and find differential preservation through time to be a problem (latest samples seem to have the most diatoms, broadly post AD 1000). This might (or might not?) incluence SiO2 measurements, but needs to be considered. Differential preservation is not discussed in the letters section of Nature Geosciences, as this is actually a long letter report rather than a final article. Once again, it looks like good work, only it’s been grand-standed just a little bit for a letter, and some conclusions require further justification (perhaps in final article?).
Bruce

Tim Clark
May 19, 2010 8:24 am

There are numerous studies, including below, that differ with this paper. I’ve read one, but couldn’t find it, that indicated an increase in temperature would be beneficial.
As mentioned above, the immense water mass of Lake Tanganyika has created a very stable environment for its inhabitants. Temperature changes, organic waste, softer rain water etcetera will rapidly be buffered by this enormous lake. This is important to keep in mind when keeping fish from Lake Tanganyika. In certain aspects, they are almost like sea dwelling fish.
Temperature wise, it is not only the large water mass, but another factor that makes Lake Tanganyika so stable – even more stable and homogenous than the ocean in most places. This factor is volcanic activity near the bottom of the lake. The temperature at the bottom of Lake Tanganyika has been measured and turned out to differ no more than 5 degrees F from the surface temperature. The stable temperature has however created sharp changes in oxygen content as you proceed down into the lake. Since there are virtually no temperature changes in Lake Tanganyika, there are no driving forces for vertical currents. Without any vertical currents and water exchange with the surface, the deep soon becomes oxygen depleted. Animals that need oxygen to survive, including of course all the Tanganyika cichlids, can therefore only be found at the top 300 meters of the lake.

Ralph
May 19, 2010 8:27 am

.
Latest BBC report – Unprecedented Warming in Lake Tanganyika – Newsnight 19:05:10
Quote:
It has been reported today that Lake Tanganyika has been warming significantly, and this may have significant ramifications for the wider global climate. Brown University graduate, Jessica Tierney, explained that this was the best freebee jolly she had been on in years, and that if she used the phrase ‘Global Warming’ enough times, she and her mates could be back for a reunion booze-up next year. Her graduate compatriot, Marc Mayes, added that getting a phd nowadays was a breeze, just make up a few temperatures that always increase, and you are guaranteed an ‘honours’.
Education minister, Kosmos Thalpo, applauded the achievements of the new generation of post graduates, and denied that these had been any dumming down of education standards.
Endquote…..
.

Pat Moffitt
May 19, 2010 8:36 am

Warrick says:
May 18, 2010 at 11:48 pm
Sardines in fresh water? I suspect they mean small tilapia (Sarotheradon species, or cichlids)
Anchovy or herring is correct -the fish are clupeids. They are thought to have evolved from a marine incursion some 25M+ years ago although still a bit of discussion on this fact. The anchovies are pelagic in nature and have a diurnal vertical migration of 200m making them difficult to target in a traditional net fishery. The top predators are latids (Nile Perch)

Dave F
May 19, 2010 8:49 am

3F since 1900? Sound the alarms! Way to prove the Earth is warming, perhaps naturally. What I did not see was any sort of proof that the warming came from CO2.
Bullet in this theory comes from the comment from Dave Springer at 8:03:
The surface warming by 3 degrees F due to the average air temperature over the lake warming by 1 degree is patently absurd.
Water is a positive feedback indeed.

Anu
May 19, 2010 8:54 am

Bujumbura, Burundi
Although the countries bordering Lake Tanganyika – Burundi, Democratic Republic of the Congo (DRC), Tanzania and Zambia – have little or no industry, and have been fishing and farming on it’s shores for millenia – researchers have now found the source of turbidity, which changes the albedo of the lake’s surface from very low to even lower, which has been hypothesized to be the cause of the lake’s warming over the last century or so.
“It’s those damn missionaries” said local scientist and fishing-net maker Didier Nkurunziza, who has been investigating the cause of the fish dying in this traditionally bountiful lake. “Every day, they trudge down to the lake to baptize some kid, and it’s not just one guy , there’s alway 2,3 or 4 other villagers helping, every day. You would not believe how muddy things get; here, let me show you some of my research data”.
http://3.bp.blogspot.com/_KvZmVkCm66w/SJ_o7reXSSI/AAAAAAAAAYs/hPj5ILi0B2k/s1600-h/PICT0569.JPG
Research data from Mr. Nkurunziza, local scientist
“The muddy water gets much warmer in the sun” said Mr. Nkurunziza, pointing to several dozen glass bottles of muddy water, and one thermometer, next to the fishing nets behind his modest home. When asked how far this muddy water travels out into the 231,000 km^2 lake, Mr. Nkurunziza laughed. “You are joking, no ? There is no measuring tape big enough for Lake Tanganyika, believe me, I’ve tried to find one.”
Westerners first found Lake Tanganyika in 1858 – Richard Burton and John Speke found it while searching for the source of the Nile river. Soon, the missionaries showed up, and the Lake began its long, dangerous warming trend.
“What else could it be ?” asked Mr. Nkurunziza. “God has sent Gustave to save Lake Tanganyika and it’s people from the missionaries.”
Gustave is a a 6.1 meter Nile crocodile living in Burundi, rumored to have killed 300 people during baptisms. While this number is likely exaggerated, Gustave has attained a near-mythical status and is greatly feared by people in the region.

Charlie K
May 19, 2010 8:54 am

Springer says: May 19, 2010 at 8:03 am
The surface warming by 3 degrees F due to the average air temperature over the lake warming by 1 degree is patently absurd.
Dave,
Possibly the lake is warming due to decreased albedo and the warmer surface temp is driving the air temp increase in the area of the lake. Living near Lake Superior, I can tell you that it is probably the lake affecting local air temperatures and not the other way around. The magnitudes you mention seem pretty reasonable to me given the lake is pretty close to the equator. Around here you can see a huge difference in air temp between the lake shore and only a mile inland. Like 10 degrees or more depending on the wind, etc.

Editor
May 19, 2010 8:57 am

Bill Illis @ May 19, 2010 at 6:45 am / provided a couple of good links. The PDF of Tierney’s previous paper in particular. It contains several items worth further study. One in particular ties Southeast Africa to the northern hemisphere. (side note: a relationship in regards to MWP comes to my mind for later investigation).

The fact that both temperature and precipitation in the
Tanganyika basin show many characteristics of northern
hemisphere climatic variability demonstrates that the northern
hemisphere has a significant influence on climate in tropical
Southeast Africa.

Back to relationship to the current paper and topic. From the PDF of the previous study I lifted part of the Tanganyika lake data image. The temp data throughout the Holocene is quite interesting. I leave it to you to place that data in context as it applies to any specific areas of personal interest. I also encourage giving the entire paper an objective reading.
The image:
http://www.leekington.com/images/Laketemps2.jpg

Fred
May 19, 2010 9:11 am

Who cares anymore what some global warming addicted pseudo scientists think or say anymore?
In their desperation to gather in the research money being shoveled off the AGW R&D truck they will now say and do anything.
They must be so disappointed they won’t get to appear on Oprah or get a few freebie trips to Bali to be feted by the media with the Jorel Scientist of the Year Award.

May 19, 2010 9:12 am

Enneagram: May 19, 2010 at 7:15 am
BTW, what about Yellowstone?
Old faithful is fine (at least for the time being).
http://www.nps.gov/PWR/customcf/apps/stream/stream.htm?parkcode=yell

May 19, 2010 9:14 am

Anu, from his article:
“…local scientist and fishing-net maker…”
heh

Milwaukee Bob
May 19, 2010 9:14 am

Nigel Harris at 7:11 am said: So, nobody is prepared to invest $18 and an hour or so to actually understand what these scientists are saying. Instead, we now know that, whatever it is that they’re actually saying, it can’t be true, because… then preceded to do EXACTLY the same thing. Nigel, what phenomenal insight do have that tells you all the people you called out are, well – “dumber than dumb”? JUST because they didn’t invest $18 and read the paper?
I sure didn’t need to. Directly from the UA Press release: The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.
And:UA geosciences professor Andrew S. Cohen (in the pink shirt) said: “We’ve got a global phenomenon driving something local that has a huge potential impact on the people that live in the region and on the animals that live in the lake.”
Nigel, any so called scientist that makes a statement wherein there is NO inclusive data to support it and NO evidence of a link, even in the most minor of ways, between any global wide phenomena and a very local condition, especially with each (in this case) being evidentially miniscule in relative size, is 1. Dumber than dumb, 2. Incompetent and corrupt, or 3. Both.
As for Why didn’t they think to come here first and find out all the real answers? Would have saved them all that heat and those flies in Africa. I reference you to 1, 2 and 3 above…. Or of course it could have been just another boondoggle African vacation, wasting tax payer money – – well, I guess that would fall under #2 above….

Robert M
May 19, 2010 9:22 am

Ah-Ha!!! The missing heat!!! Found it at last!

Paddy
May 19, 2010 9:52 am

It seems that Lake Tanganyika is eutrophyic in addition to accomodating increased infusions of sediments. The sources of phosphate and nitrate infusions need to be found and mitigated. Otherwise the dead zone will continue to expand upwards. The algae blooms that cause the eutrophy must also be one of the causes of increased water temperatures.

Rich Matarese
May 19, 2010 9:57 am


Nigel Harris chides those who comment here for not wanting to cough up $18 to Nature Geoscience to read through the single letter which is the source of this AGW propaganda puffery, and gripes at me for observing that “measuring only surface temperatures tells you nothing about total heat accumulation” in a body of water.
Nigel, dear boy, have you downloaded a PDF of that letter for your own close examination? The supplementary information on this letter is freely available from Nature Geoscience (see http://tinyurl.com/27tfgx3 ), and if the references listed therein are the only references cited in the letter itself, I take this as a strong indication that the investigators participating in this study indeed did not assess temperatures of the lake’s waters even at the points where they took the two core samples (MC1 and KH1) discussed in that supplementary information.
I have also wondered why the hell the authors of this letter seem not to have taken into full consideration other actors in the ecology of the Lake Tanganyika area which the average biologist would immediately appreciate as powerful confounding factors in any quest to use changes in sediments and/or surface waters as validation of the anthropogenic global warming hypothesis (which, remember, attributes a putative acceleration of the slow and rather steady rebound in global average temperatures since the close of the Little Ice Age ca. 1850 to increases in atmospheric CO2 concentrations as the result of fossil fuels combustion, and advances the claim that reduction in such CO2 releases as the result of purposeful human action can reverse this so-called “catastrophic” trend).
Are there indications that Tierney et al (or the referees reviewing this letter) had some thoughts about the ways in which processes other than AGW could account for the physical findings they observed? Is there any indication that they made reference to (or conducted en passant) such simple observations of surface water turbidity, chemical composition, microflora, and suspended particulates as would occur instantly to anybody with a bachelor’s degree in biology?
Paleolimnology is all well and good, but what settles down there on the bottom tends (with the exception of human artifacts like the hulk of the Hedwig) to be the result of activity in the biosphere above, both in the lake itself and in the tributary streams contributing thereunto.
Given that part of what the AGW alarmists are whining about in their propaganda pivoting on this letter is the reduction of productivity in Lake Tanganyika’s fisheries – which they immediately and loudly trumpet as proof of man-made global warming – I find that a failure to look at other easily discerned and much more immediately efficacious mechanisms as principal causes of reduced fish catches glares.
Don’t you, Nigel?
Hm. Nigel, have you any experience of academic publishing in the sciences? I do. I’ve even participated in the process which is known as “baloney-slicing,” the careful and parsimonious utilization of investigational data to maximize the number of publications (and the impact factor of each such publication) to be derived from time, effort, and funds invested in a particular study.
I have therefore some proximal professional insight into what this letter of Tierney et al represents in the scheme of things up at Brown University’s department of geology as well as how it fits into the confabulations of the AGW cabal.
I don’t think you, do, Nigel. But what the hell. Have you given Nature Geoscience your VISA account number and downloaded a PDF of this letter?
If so, would you please tell us what you’ve found?
For my own part, I’ve passed along to Dr. Lindzen at MIT the Web addresses of the letter itself and the supplementary information so that he might review it, or consult with one of his colleagues up there about it, as he might elect.
But I no more intend to cough up cash for a copy of this letter than I expect Dr. Tierney to plunk down Federal Reserve notes for access to something from The Journal of Virology or Gastroenterology.
Clinical medicine is not her field, and geology is not mine. But scientific method is uniformly applicable in both, and it is not only possible but inevitable that people trained and experienced in disciplines other than that of Dr. Tierney and her colleagues will examine the work they make public, cock an eyebrow, and say:
“Something reeks about this.”

Pat Moffitt
May 19, 2010 10:03 am

Nigel Harris says:
May 19, 2010 at 7:11 am
it’s clearly impossible [implies Pat Moffit’s rhetorical question] to say anything about historical surface temperatures from core samples taken from the bottom of a lake
Read what I wrote- I am skeptical but I asked a question. Perhaps you can tell me how a sediment core from over 570m below the surface of the lake can be calibrated to show a change in surface temperature of 1.7C.
And if scientists stopped using media as a propaganda tool before anyone has had a chance to read the paper or do a review we wouldn’t have had this little spat.

Billy Liar
May 19, 2010 10:28 am

Seems to me that an ill thought out press release can do a lot of harm to your reputation as a scientist (assuming you have/want one).

Nigel Harris
May 19, 2010 10:34 am

Milwaukee Bob,
I didn’t accuse anyone of being dumber than dumb. If you read what I wrote, I was (ironically) accusing the scientists who did the research of being dumb for not having realized that their research was pointless because of all the facts that I listed that are apparently self-evident to WUWT posters. All I’m accusing WUWT posters of is rushing to judgement without actually bothering to read the paper (or letter) in question.
Although, now I think of it, “dumber than dumb” is a pretty good description of some of the comments appearing above, so it is understandable that you thought that’s what I meant. That is, of course, what I think. I’m going to have to try to find another site where I can find genuine, scientific scepticism about AGW, not uninformed knee-jerk condemnation of other peoples’ work.

Bruce Cobb
May 19, 2010 10:42 am

Nigel Harris says:
May 19, 2010 at 7:11 am
Why didn’t they think to come here first and find out all the real answers? Would have saved them all that heat and those flies in Africa.
They aren’t interested in real answers (~snip~). They already “know” that the warming of the surface , and all the other problems mentioned is due to “manmade warming”, and that it will therefor just keep getting worse. The manmade warming bogeyman saves them the work of looking for other possible causes.

Nigel Harris
May 19, 2010 10:52 am

Pat Moffitt,
I realise you asked a question, and it is possible that you were perfectly genuinely seeking knowledge. But if so, why not do some research yourself? The summary of the letter, which is available at nature.com (link in Rich Matarese’s comment above) mentions that they use the TEX86 temperature proxy. It is easy to learn about how that works, at least in principle, online. There’s even a short Wikipedia page on it, but you can access several original papers in full, on Google Scholar, for instance. In 5 minutes research, I have learned that some phytoplankton respond to temperature changes (at/near the surface where they live) by changing the chemical composition of their membranes. When they die, they sink to the bottom and become part of the sediment. The membrane components are preserved, so by analysing the chemical composition of the resulting sediment at the bottom of the lake, you can build up a historical temperature profile of what was happening at the surface of the lake.
Now I apologise if I have done you a disservice by interpreting your question as a statement of disbelief. However, this is a very common rhetorical trick used on these sorts of blogs to inject uncertainty and doubt where there is no reason for it. I (maybe wrongly) suspected you were asking the question to ridicule the authors of the work, rather than in a genuine pursuit of knowledge, for the simple reason that if you really wanted to know, you could have found out for yourself in less time than it took to write your comment.

Mike
May 19, 2010 10:54 am

Anthony Watts said “Unfortunately in these press releases there is no mention of a possible increase in turbidity due to human action on and around the lake, decreasing the albedo to absorb more sunlight on the lake surface, warming it.”
Here is the abstract to the article. Unfortunately I cannot access the full article because my university’s library does not have a subscription due to (I assume) budget cuts in recent years.
(Bruce already posted it.)
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo865.html
I did find this. The Nyanza Project helped fund the study. This was from their website:
“In recent years Lake Tanganyika, like many other large lakes of the world, has begun to feel the effects of a variety of human impacts, including fishing pressures, an increased rate of sediment accumulation along rocky coasts caused by deforestation and soil erosion in the lake’s watersheds, and climate change.”
http://www.geo.arizona.edu/nyanza/study.html
Thus, it is very likely the researchers were aware of the issues Anthony raised, although I have no idea how they handled it. Press releases are not likely to be complete.
It is unfortunate that access to journal articles is so difficult. In my field, mathematics, we post preprints for free before articles even come out. Journals are viewed mainly as final repositories. Physics is the same. I do not know why other fields do not do this.

Rich Matarese
May 19, 2010 10:56 am


Tim Clark (at 8:24 AM) had pulled a pair of paragraphs without attribution, and it would be appropriate to spot the citation, which is a one-page online article titled “Lake Tanganyika and the Tanganyika cichlids” at http://tinyurl.com/24az8ak
A more reliable citation would be appreciated, particularly with regard to the assertion that there is significant “…volcanic activity near the bottom of the lake” which so affects the heat content of these waters that “The temperature at the bottom of Lake Tanganyika has been measured and turned out to differ no more than 5 degrees F from the surface temperature.
This is (to use the phrase made famous by Hairplug Joe, our brain-damaged Vice President) “a big [copulating] deal,” and warrants a great deal more focused consideration.
As I had previously recounted here, I have gotten spew from warmist fellahin to the effect that there is no real and appreciable contribution of vulcanism to the temperatures recorded in the waters of Lake Tanganyika, meaning that whatever heat is imparted to that puddle must come from deadly, evil, “only-Man-is-vile” anthropogenic atmospheric warming.
Anybody else got anything on magmatic cookery at the bottom of Lake Tanganyika? If so, now would be a good time to get it out here.

.

Enneagram
May 19, 2010 11:04 am

Nigel Harris says:
May 19, 2010 at 10:34 am
I’m going to have to try to find another site where I can find genuine, scientific scepticism about AGW, not uninformed knee-jerk condemnation of other peoples’ work.
You won’t find believers here, we are just doubters, we do not kneel before any Holy Climate Prophet.

Retired Engineer
May 19, 2010 11:06 am

A question some have hinted at: How has the population grown around this lake in the past 100 years? A fishery for thousands of years, perhaps, but how many catchers of fish? And what of pollution, runoff and the like?
Seeing the specks and not the logs.

Enneagram
May 19, 2010 11:07 am

There is too much anger in the Green Church believers, so I would suggest to decriminalize pot to calm them down.

Rich Matarese
May 19, 2010 11:31 am


Mike laments:
It is unfortunate that access to journal articles is so difficult. In my field, mathematics, we post preprints for free before articles even come out. Journals are viewed mainly as final repositories. Physics is the same. I do not know why other fields do not do this.
The one-word answer, Mike, is publishers. The publishing companies which have established something close to an oligopoly in academic periodicals are determined to wring every last centavo from their “intellectual properties,” and those of us in the medical field regularly damn Elsevier, Wolters Kluwer, et alia for the costs they impose upon practicing clinicians without academic affiliations (and therefore lawful online access through libraries’ subscriptions) to full-text information they hold more closely than Disney guards Mickey Mouse.
A great many medical journals will permit unpaid access to their contents after six months to a year of proprietary “hold,” and others do so immediately as they decide to publish. See http://www.freemedicaljournals.com/ for some insight into what is and is not denied to the non-subscriber in the field of health care.
Many of the publishers, however, will never permit free distribution of content except when such access is given as a “sample” or when a supporter subsidizes such access as a sort of na levo marketing ploy to tout the results of something like a particularly advantageous clinical trials report.
An article can be literally fifty years old (or older) and a company like Elsevier will demand cash up front before a speckled and ratty PDF scan of the original pages can be lawfully downloaded from their Web site.
It’s stuff like this that gives me cause to foster sympathy with author Cory Doctorow and the other advocates of rationalizing intellectual property rights.

Mike
May 19, 2010 11:32 am

Billy Liar said (May 19, 2010 at 10:28 am): “Seems to me that an ill thought out press release can do a lot of harm to your reputation as a scientist (assuming you have/want one).”
Good point. You might be interested in this.
How not to write a press release – gavin @ 21 April 2006:
http://www.realclimate.org/index.php/archives/2006/04/how-not-to-write-a-press-release/

Grumbler
May 19, 2010 12:12 pm

“Nigel Harris says:
May 19, 2010 at 10:34 am
……..I’m going to have to try to find another site where I can find genuine, scientific scepticism about AGW, not uninformed knee-jerk condemnation of other peoples’ work.”
Don’t leave. Stay a while and change our ways. We aren’t zealots, just critical thinkers. And yes we do read papers when we need to but as they all conclude with ‘it’s AGW’ it gets a bit boring. I think what many of us are objecting to is the press release and alarmism not the subtleties of the paper. Does it matter what the paper says. Perception is truth.
We object to the way the science is communicated.
cheers David
cheers David
cheers David

Grumbler
May 19, 2010 12:14 pm

Oops, 3 cheers for Nigel 🙂

DesertYote
May 19, 2010 12:40 pm

I seem to remember Tanganyika having a deleterious affect from the introduced fish, Lates niloticus. I have not kept up as the rift lakes, though incredibly fascinating and unique, are not a current interest of mine, so my knowledge is a bit dated. I am not convinced that this is a real issue (e.g.. was originally promoted to make Mankind look evil because of dams). Lake T has its own Lates, i.e. L. angustifrons. I have personal experience keeping L. calcarifer. All of these guys are pretty similar. Mine consumed a lot of food.

Pat Moffitt
May 19, 2010 1:10 pm

Nigel-
I did check out the homepage for TEX86 proxies which is why I wrote the question -How can they claim to see a 0.9C increase. Take a look at their correlation with sea surface temperatures http://members.quicknet.nl/ellenstefan/index_files/Page365.htm and tell me how the authors of this paper can claim sensitivity to 0.9C over a very abbreviated temperature range. Also note the caution on the TEX86 site that it is an “empirical correlation and many questions remain unanswered”
You should also be aware that many of the Lake’s bays are eutrophic while the open waters seem to becoming more oligotrophic. One can as a result have two different temperature trends as a result of the differential heating in the presence of organic or inorganic particulates.
Also take a look at the variability of of the lake vertical temperature distribution http://www.ilec.or.jp/database/afr/afr-06.html which also raised my concern of a 0.9C. It is also the reason for my reaction to their reliance on only two or three core samples.
I have done a fair amount of investigation on the problems with the latid and clupeid fishery (sociological and ecological) in both Lakes Victoria and Tanganyika- outside this scope. There are any number of pressing problems with these fisheries and the impacts are potentially large to the local human population. For the researchers to “imply” that CO2 induced temperature changes represents a significant concern for the lake or the residents is wrong on too many levels. The residents of Lake Tanganyika’s shores are unfortunately facing far more pressing near term threats to survival– and any chance we had to “fix” these problems of overfishing, deforestation (fire wood), pollution, habitat loss, agriculture run off, civil war, etc are now diminished because the tool set has been restricted to CO2 reduction. A good test would be checking back in a year and see where aid and research money was spent– addressing the region’s “problems”.
Remember it is actually wind that causes the upwelling (the density difference related to T being quite small) and as such these researchers have to make some serious leaps in correlating wind speed with temperature to make the nutrient links.
“If” the problem is actually some reduction in productivity as a result of nutrient deficiency — then the answer is pretty simple- add fertilizer. The efficacy of this is quite well know and has been researched and demonstrated extensively with salmon populations (replacement of decaying salmon nutrients -MDN- lost to high seas commercial fishing with commercial fertilizer causing an increase in salmon production of 3 to 5X the baseline) as well as with warm water fish populations.
I would have had less of a reaction had these researchers mentioned the fact that nutrient addition would cause an immediate increase in the lake’s food production and the well being of the resident human population– whether or not climate change is real. Failing to tell the media that an easy nutrient fix is available or how CO2 ranks with the other problems faced in this region-in my view is unethical and immoral.

Anu
May 19, 2010 1:11 pm

Mike says:
May 19, 2010 at 10:54 am
It is unfortunate that access to journal articles is so difficult. In my field, mathematics, we post preprints for free before articles even come out. Journals are viewed mainly as final repositories. Physics is the same. I do not know why other fields do not do this.

Yes, scientific papers should not be behind paywalls on the Internet – having them published on paper and sold for exorbitant prices to University libraries is probably holding back the progress of science, if only a little (although the Journals argue this pays for the peer-review process, and they are doing a service). It looks like there is movement towards free access to published papers on the Web, even if only after 12 months
http://www.wired.com/wiredscience/2009/03/openmit/
For instance, the NIH now (since 2008) requires NIH funded research papers to be made public 12 months after publication. As the person who spearheaded the MIT open access policy said: “Who actually should be controlling the scholarly record? Universities have a mission that has something to do with producing and disseminating knowledge. These publishers, whatever their good intentions may be, have a mission to make money for their stockholders. The system is a little out of whack.” Open access advocates say the current scientific publishing paradigm is broken because publishers control the scientific record, not academics.

Milwaukee Bob
May 19, 2010 1:16 pm

Nigel Harris, sorry IF I mistook your intent….. But you now say: Although, now I think of it, “dumber than dumb” is a pretty good description of some of the comments appearing above, so it is understandable that you thought that’s what I meant. That is, of course, what I think. so your saying when you first listed them you thought they were ALL valid and dare I say “thoughtful” comments the scientist should have thought “about” BUT NOW you think SOME of them are dumb (what does THAT say about you?) – – but not all – – and because not ALL of them are stimulating scientific points – – your going to go find a “better scientific website” with no knee-jerking? Well, lots of luck with that and don’t let the cyber door….. Well, never mind, that’s not my call.

Mike
May 19, 2010 2:02 pm

Rich Matarese said (May 19, 2010 at 11:31 am):
“The one-word answer, Mike, is publishers. The publishing companies which have established something close to an oligopoly in academic periodicals are determined to wring every last centavo from their “intellectual properties,” and those of us in the medical field regularly damn Elsevier, …”
I know, I know. But we in math refused in mass to let them get away with it. I always post my articles regardless of the copyright terms the journal has. We all (in math) do this. They never touched us. We closed down one Elsevier journal when it wouldn’t lower its price to libraries. (http://www.ams.org/notices/200007/forum-birman.pdf) Also, Nature is not a for profit group. Why are they blocking access? And JSTOR, why do they block access? Maybe they could limit advanced search features to subscribers so libraries would keep paying. Someone does have to pay.
Anu: Good to know that about NIH. Maybe NSF and DOE will follow. But a one year delay still limits public discuss. Reporters and bloggers should not be limited to relying on press releases.

Rich Matarese
May 19, 2010 2:16 pm


Anu writes of how “…the Journals argue this [charging big bucks for access to individual articles in their archives] pays for the peer-review process….”
Hm? I’ve done peer review for academic journals. I got nothing for my time and trouble except a pro forma “Thanks, Doc!” and a listing way to hellangone down the masthead as a halfway-honorary member of the editorial staff.
I suppose some guys like sticking such mentions in their curricula vitae, but how the devil does it cost a journal anything in terms of real resources (especially these days, when everything is conducted by e-mail, and the manuscripts come to reviewers as digital file attachments) to conduct peer review?
Anybody else have experience in the peer review process? Has anyone ever gotten paid to do this kind of work?

Mike
May 19, 2010 2:34 pm

I never get paid to review articles. Textbooks companies have paid me to review drafts of their books on two occasions.
One point about access to journals. Public universities in the U.S. will allow state residents to purchase library cards for a modest fee. I would assume that this would include an access code for their e-journal subscriptions. Those of you who aren’t academics should be able to get access this way. I would encourage you to do so. As a state resident your taxes pay for these journal subscriptions.

May 19, 2010 2:41 pm

The cavalcade of published papers based on underdone research continues to amaze me, indicating the peer review process, for a few journals at least, has run off the rails.
This paper a classic case in point. It reads like a research proposal, putting forward a hypothesis, but the data presented at this point in time is hardly compelling being insufficient to prove the point and thus hardly deserving of publication.
The sad thing is that the junior researchers involved will go away believing this is how science is done!
I wonder if the authors are brave enough to comment.

George E. Smith
May 19, 2010 2:55 pm

Totally amazing; that there can be millions of people feasting off the fisheries of Lake Tanganyika, and all of that human hustle and bustle is carried on without stirring so much as a blade of grass on the shoreline so as to cause some mud to fall into the lake.
Those African Tribes are simply geniuses; like the tribes who have lived for thousands of years on the plains around the base of Mt Kilimanjaro; without anybody ever disturbing a branch on a tree growing in the vast rain forests on those plains.
We should all be such stewards of our natural surroundings.

Rich Matarese
May 19, 2010 3:03 pm


Mike, thanks for access to Birman’s forum article (Notices of the AMS, August 2000). I’ve got my nose right up against the world of clinical medicine (like most of us in the sawbones racket), and confess freely to damned little fine appreciation of what goes on in other disciplines.
Among the problems in medical academic publishing is the fact that it’s bloody expensive to conduct clinical research, especially to the standards very properly established in the usages of evidence-based medicine, which is where those of us with Betadine on our shoes have been trying to propel the medical literature for the past decade and a half.
With this in mind, it must also be remembered that to practice medicine in these United States today, it is effectively impossible not to hold board certification in one or another of the clinical specialties, and that makes de rigeur membership in one or more of the professional societies – ACOG, IDSA, AAP, AASLD, pick your acronymic lump – because you must keep up with developments in your specialty area, and the professional societies are, all other things being equal, the best conduits of information.
The publications of these professional societies therefore become hellaciously important, and the big publishing companies – like Elsevier and Wolters Kluwer (who own the Lippincott Williams & Wilkins journals) – run those periodicals.
Okay, so couple the very high real monetary costs of conducting prospective clinical investigative trials (which are almost exclusively funded by pharmaceuticals and medical device manufacturers) with the fact that these proprietary-to-obsession publishers control the principal fora in which the reports of medical research are promulgated, and you can see that those of us in medicine have a boatload of troubles which effectively prevent us from doing the sorts of things that you guys in mathematics (who work with chalkboards and computers and don’t have to pay for lab supplies, sutures, and professional liability insurance) can manage when it comes to ensuring academic rigor and freedom.
You guys can walk away from a professional society or other institution if you deem the conduct of the ruling elite objectionable enough. Moreover, said “elite” know good and goddam well that you can, which acts as a control on their officious weaselry.
People who get their living on the basis of being able to call themselves “board-certified” (you try getting on a hospital staff without such) can’t even put food on the table much less conduct good research without jumping through the ever-narrowing and ever-more-scorching fiery hoops set up by our predecessors.
I have no reason to believe that it’s not quite similar in the other get-your-hands-dirty sciences, like astronomy, geology, meteorology, atmospheric physics – even “climatology.”

Gail Combs
May 19, 2010 3:13 pm

pesadilla says:
May 19, 2010 at 5:35 am
The concept of climate change has evolved to the point where it no longer needs co2 in order to create havoc. It is now a phenomenon in its own right. (possibly like dark matter). The phrase is most useful in obtaining grants for scientific studies and is more than capable of generating large amounts of money in order to perpetuate itself. It even has its own laws like azimovs robotics laws…..
I clean them up a bit for you. They are too good to let grammar and spelling mess them up. Corrections are in bold.
0)all projects that confirm the existence of AGW will be supported and funded generously and without question.
1) Any new project which is intended to support the first law will also be funded.
1) Any project containing the words “green” “renewable” or “endangered” etc will be seriously considered, provided that their findings do not conflict with the other two laws.
___________________________________________________________________________
Excellent! I have taken the liberty of renumbering the Laws of ACC (after messrs. Fibonacci, Wm. of Occ’m, & Codd and Date)

Gail Combs
May 19, 2010 3:31 pm

Thanks Tim and Bruce for the research.
________________________________________________________________________
Tim Clark says:
May 19, 2010 at 8:24 am
“There are numerous studies, including below, that differ with this paper…..
Temperature wise, it is not only the large water mass, but another factor that makes Lake Tanganyika so stable – even more stable and homogenous than the ocean in most places. This factor is volcanic activity near the bottom of the lake…..”

________________________________________________________________________
Seems Vukcevic is correct. It is probably volcanic heating especially since we seem to have more sesmic activity lately. Bruce, did the paper make any mention of “…volcanic activity near the bottom of the lake…”

Michael
May 19, 2010 3:35 pm

“The team’s article, “Late twentieth-century warming in Lake Tanganyika unprecedented since AD 500,” will be published in the June issue of Nature Geoscience.”
The team’s article, Late twentieth-century warming in Lake Tanganyika not unprecedented since AD 1250 Medieval Warm Period when the lake was significantly warmer due to increased solar activity, will be published in the June issue of Nature Geoscience.
There, fixed it for ya.

Jim Barker
May 19, 2010 3:38 pm

Slightly OT, but I saw an ad for a temperature data-logger that looked very nice. It seems as though it would make lake temp measurements much easier.
Look Ma, no driver — temperature logging via USB
Spurring the growth of PC-based data-acquisition (DAQ) systems is a wealth of new instrumentation systems designed to work with PCs. One such device is National Instruments (NI) USB-TC01, a USB-connected data-acquisition module that measures and records temperature via a thermocouple. The new device combines a plug-and-play setup with the capabilities and features of other NI DAQ products.
What makes the USB-TC01 noteworthy is that it needs no setup time or driver-software installation. Known as NI InstantDAQ technology, the device automatically loads everything the computer needs to take and record temperature measurements when plugged into a USB port. In addition, the module features a standard miniplug connector that lets the logger use different thermocouples to meet specific application needs.
The USB-TC01 offers temperature measurement and logging for applications in scientific labs; heating, ventilating, and air-conditioning (HVAC) units; cryogenics; industrial ovens and furnaces; engine-exhaust and combustion systems; building monitoring; and many other environments. In addition to saving time and resources in system setup, the device also exhibits the overall accuracy and reliability of more-complex measurement systems. With traditional stand-alone data loggers, measurements are made independently of the PC so data can only be viewed offline. The USB-TC01 is always connected to the PC so it can take live measurements with temperature readings displayed instantly on the PC monitor.
Optional free applications available at http://www.ni.com expand the basic functions of the USB-TC01. Or the USB-TC01 can be combined with NI LabView graphical-system-design software using the NI-DAQmx driver software.
REPLY: Or see these that I offer: http://weathershop.com/dataloggers.htm – Anthony

BillD
May 19, 2010 3:48 pm

As a lake ecologist who has read a few dozen publications of Lake Tanganika, I recomend reading a part of the scientific literature before pronouncing judgement on one paper that builds on the earlier work. I recommend a 2009 paper that is available from ASLO.org as a free download.
http://www.aslo.org/lo/toc/vol_54/issue_6_part_2/2418.pdf
Unfortunately for Mr. Watts’ speculation, the water of this lake has become clearer since 1913. Reduced nutrient mixing due to stronger and shallower stratification evidently over rides effects of land use in the basin.
The best paper on these issues is probably Verburg and Hecky 2003 (Science).
Quite a lot of the literature on this lake should be available as free downloads–try searching using Google Scholar. These paper also talk about the equipment needed and the accuracy in measuring temperature of such a deep lake.

Gail Combs
May 19, 2010 3:52 pm

Enneagram says:
May 19, 2010 at 11:07 am
There is too much anger in the Green Church believers, so I would suggest to decriminalize pot to calm them down.
________________________________________________________________________
Yes and make hemp, a very useful plant, legal too.
Hemp for Victory. USDA, 1942 http://www.globalhemp.com/Archives/Government_Research/USDA/hemp_for_victory.shtml

May 19, 2010 4:03 pm

Nigel Harris says: May 19, 2010 at 7:11 am
“So, nobody is prepared to invest $18 and an hour or so to actually understand what these scientists are saying. Instead, we now know that, whatever it is that they’re actually saying, it can’t be true, because…
“… David L’s pool in Philadelphia isn’t any warmer than it was 5 years ago”
Actually I got the paper. I spent half my career as a PhD in Ivy league universities grubbing for grants and publishing in peer reveiwed journals. I know how the system works. Terms like “Global Warming” will get you grant money, trust me. Happily the past 10 years I’ve been developing safe and effective drugs with my chemistry degree.
My somewhat tongue-in-cheek comment about my pool is about how I feel about AGW. From a thermodynamic standpoint can you explain to me how a massive lake warms by 3 degrees due to a global effect like CO2 yet my tiny little pool (which is on this globe) sees a negative effect of 5 degrees in the past 5 years. No CO2 in Philly, it’s all in Africa? (which place is more industrialized by the way) Thermodynamics only apply to Africa? Local weather patterns are different? If you’re going to claim the globe’s temperature is driven by a single large factor (like CO2) then that should drive the effect all over the globe, shouldn’t it? (or it wouldn’t be a global problem). Otherwise you have to admit that it’s either not that large of a factor, or it’s tempered by other factors and their interactions with each other. And then you have to admit you don’t really understand everything about the science, because you can’t explain all the effects around the globe. So tell me, if CO2 is a nice cozy blanket that traps heat, why isn’t it happening in my backyard? I had to wear my winter coat to work today. 100 years ago on this date it was 82F.

Anu
May 19, 2010 4:16 pm

George E. Smith says:
May 19, 2010 at 2:55 pm

Yes, the locals have lived like ninjas for thousands of years around the Lake – you can’t even hear them walking, barefoot on the dirt roads. And the fishermen slip into the water without a sound, the result of hundreds of generations of living with crocodiles. Then the missionaries came in the late 1800’s, with their thousands of clumsy, turbid baptisms every day, and the Lake began to warm, until we’ve reached the current crisis.
This has been researched by Mr. Nkurunziza (see above), an expert on Anthropogenic Local Warming (ALW) in Burundi. His policy recommendations to the IUCN for returning Lake Tanganyika to it’s optimal temperature: capture and breed Gustave, the supercroc, and seed the shores all around the Lake with these future maneaters. “I’ve seen the missionaries run away from the water screaming like little girls when they thought they saw Gustave approaching” said Mr. Nkurunziza, laughing. “Keep them out of the Lake, and the mud will settle quickly. Problem solved. The Lake will cool down.”
http://adventure.nationalgeographic.com/2005/03/gustave-crocodile/michael-mcrae-text/1

Gail Combs
May 19, 2010 4:25 pm

#
Pat Moffitt says:
May 19, 2010 at 1:10 pm
“……I have done a fair amount of investigation on the problems with the latid and clupeid fishery (sociological and ecological) in both Lakes Victoria and Tanganyika- outside this scope. There are any number of pressing problems with these fisheries and the impacts are potentially large to the local human population. For the researchers to “imply” that CO2 induced temperature changes represents a significant concern for the lake or the residents is wrong on too many levels. The residents of Lake Tanganyika’s shores are unfortunately facing far more pressing near term threats to survival– and any chance we had to “fix” these problems of overfishing, deforestation (fire wood), pollution, habitat loss, agriculture run off, civil war, etc are now diminished because the tool set has been restricted to CO2 reduction. A good test would be checking back in a year and see where aid and research money was spent– addressing the region’s “problems”.
Remember it is actually wind that causes the upwelling (the density difference related to T being quite small) and as such these researchers have to make some serious leaps in correlating wind speed with temperature to make the nutrient links.
“If” the problem is actually some reduction in productivity as a result of nutrient deficiency — then the answer is pretty simple- add fertilizer. The efficacy of this is quite well know and has been researched and demonstrated extensively with salmon populations (replacement of decaying salmon nutrients -MDN- lost to high seas commercial fishing with commercial fertilizer causing an increase in salmon production of 3 to 5X the baseline) as well as with warm water fish populations.
I would have had less of a reaction had these researchers mentioned the fact that nutrient addition would cause an immediate increase in the lake’s food production and the well being of the resident human population– whether or not climate change is real. Failing to tell the media that an easy nutrient fix is available or how CO2 ranks with the other problems faced in this region-in my view is unethical and immoral.”

________________________________________________________________________
Thank you.
Making CAGW the “boogeyman” no matter what the real cause is resulting in major damage. This fact seems to sail right over the heads of the “environuts” Whether you think CO2 is causing warming and is cause for concern or not, blindly supporting irresponsible “pseudoscience” such as this IS doing real harm to the environment and the people of the region. Responsible environmentalists should be actively pointing out the harm these quacks are doing, just as medical Doctors should denounce snake oil salesmen.

Jim Barker
May 19, 2010 4:25 pm

Here’s a link to a picture of the one I mentioned.
http://machinedesign.com/content/single-channel-thermocouple-0503

Gail Combs
May 19, 2010 4:38 pm

Mike says:
May 19, 2010 at 2:34 pm
“…. Public universities in the U.S. will allow state residents to purchase library cards for a modest fee…..”
____________________________________________________________________________
Thanks for the tip Mike. I guess if worse came to worse you could “donate” a subscription to the local community college at their reduced fee AND take the “donation” off your taxes.

BillD
May 19, 2010 5:31 pm

I don’t really understand the criticism of studies without reading the original study or any of numerous background papers on the same lake. I mentioned this paper, which is availble from the top rated Aquatic journal as a free downloald:
http://www.aslo.org/lo/toc/vol_54/issue_6_part_2/2418.pdf
Among other things, this paper shows that the open waters of the lake have become substantially clearer (less turbid) over the last 100 years. The temperature data for the deepest waters show that geothermal heating is neglible and could not possibly effect the temperature of the top 100 m, the focus of most studies. The paper that Anthony cites in his lead in shows effects of run off and polution in the shallow, near shore waters to a depth of 80 m, especially near river inflows. Clearly this is a problem for the littoral, rocky bottom fish, that comprise most of the species diversity. However, since this is one of the largest lakes in the world, these nutrient inflows evidently have very little effect on the nutrient content, turbidity and productivity of the open waters of the lake (average depth over 500 m). In these main, open waters of the lake effects of climate warming on stratification and nutrient regeneration are very strong over the last 100 years. Readers should not make knee jerk conclusions without reading data rich papers that conflict with their expectations.

BillD
May 19, 2010 6:23 pm

Gail Combs says:
May 19, 2010 at 4:25 pm
#
Pat Moffitt says:
May 19, 2010 at 1:10 pm
“……I have done a fair amount of investigation on the problems with the latid and clupeid fishery (sociological and ecological) in both Lakes Victoria and Tanganyika
I did both Google and Google Scholar searches on Patrick and did not find anything beyond blog posts. He suggests that adding nutrients might be a simple solution to the reduced productivity of the lake with a volume of over 18,000 cubic km. This solution has worked well in small salmon lakes with on the order of 0.001% of the volume of L. T. but fertilizing such a big lake and deep where nutrients are quickly lost to depth may not be a simple solution IMO.

Rich Matarese
May 19, 2010 6:44 pm


BillD, thank you for access to Verburg & Heckey (Limnol. Oceanogr. 2009, pp. 2418-2430) on “The physics of the warming of Lake Tanganyika by climate change.” I’m going through the paper with attention to the “Discussion” session, runs from page 2421 through page 2439.
Big damned “Discussion” section, ain’t it?
From page 2425 I draw the following:
The recent net global forcing that drives climate change amounts to 0.85 W m22 (Fig. 9; Hansen et al. 2005), six times the mean of the past century (Fig. 9B). Modeling indicates that lakes will absorb less net heat than is applied by local climate forcing (Fig. 9), by enhancement of their heat outputs through the interaction with the atmosphere. Deep lakes, however, have the capacity to absorb more heat than shallow lakes, and in a warming climate heat outputs will increase more slowly in deeper lakes than in shallower lakes. This inherent tendency toward greater heat absorption with little change in surface temperature in deeper lakes will be reduced if the lakes become increasingly stratified as warming progresses, as has been the case in Lake Tanganyika.
The global hydrological cycle is expected to accelerate with climate change (Wentz et al. 2007), and global evaporation has been predicted to increase (Ramanathan 2001), which agrees with our conclusion of increased heat outputs, in part through evaporation, by most lakes. The extent to which evaporation from inland water surfaces will change in a changing climate not only affects the heat budget and stratification of the water column but will also be of great importance to the water balance and water levels in lakes and to the availability of freshwater in a warmer world

Oh, drat. Drawing on Hansen’s models. Seems as if Drs. Verburg & Heckey are paying tribute to the AGW fraud, aren’t they?
Grinding repeatedly through the paper, I’m not sure if I’ve yet found something that I can honestly call a conclusion. I don’t contest the authors’ assertion that:
Climate warming has affected the physical structure of Lake Tanganyika and substantially affected the functioning of the pelagic ecosystem
…but there is that highly damning concluding sentence to all this “Discussion,” to wit:
Although African ecosystems are remote from most of the anthropogenic activities that have driven climate warming, the Great Lakes of Africa and their riparian human populations have not and will not escape its effects.
So Drs. Verburg & Heckey consider themselves to have done what they set out to do, which was not so much to determine how the waters of Lake Tanganyika are changing in response to the well-understood rebound in global temperatures since the conclusion of the Little Ice Age but rather to validate the anthropogenic global warming hypothesis.
Which they fail to do, you understand. Drs. Verburg & Heckey observe warming. That’s fine. There’s hard evidence of that.
Is there hard evidence in their observations proving that there has been substantial acceleration in the rates at which that warming – since 1850, remember – has been pumped up by anthropogenic increases in atmospheric carbon dioxide concentrations, or are they simply falling back on Dr. Hansen’s computer models?
There is much made by the authors of expectations (Wentz et al. 2007) and predictions (Ramanathan 2001) with which Drs. Verburg & Heckey’s conclusions have been made to agree, but I’d be grateful if you – or anybody – could show me how the warming trends demonstrated by the observational data subjected to meta-analysis in this study provide support for the AGW hypothesis.
Anent that meta-analysis (’cause it sure as hell looks like a meta-analytical paper), did either Dr. Verburg or Dr. Heckey actually do any field work resulting in information analyzed to produce this publication? In the “Acknowledgments” section there is mention made of “the deployment and maintenance of recorders” conducted by “Personnel of the Fisheries Departments of Burundi, Congo, Tanzania, and Zambia” and how “Thermistor data in 1994–1996 were collected as part of research conducted by the Project for the Management of the Fisheries of Lake Tanganyika, Food and Agriculture Organization (GCP/RAF/271/FIN),” but not a whole helluva lot of sneakers-on-the-riverbank sweat equity appears to have been invested here.
But that’s neither here nor there. Again, the focus should be – when examining this wealth of information – on whether or not what has been happening in Lake Tanganyika provides insight into some sort of climate change which is distinctly different in character from the relatively slow, relatively steady rebound in global temperatures that has been observed since the end of the Little Ice Age.
If carbon dioxide forcing were a significant factor in this climatic warming, then as the atmospheric content of carbon dioxide isotopically identifiable as resulting from the combustion of fossil petrochemicals has been very rapidly increasing, there really ought to be some proportionality in the rate of increase in average temperature, no?
Am I missing something in Drs. Verburg & Heckey’s paper? If so, I’d ask for a helping hand.

Henry chance
May 19, 2010 6:54 pm

Silent spring for Mongolians after winter kills herds
The long, cold winter killed an estimated 8 million animals, leaving impoverished herders struggling to survive.
Oops Jesica needs to frame her story to include the planet. He little study 7 years ago has be followed cattle frozenon the hoof.
A real honest scientist needs to take some cores all over the planet.

SSam
May 19, 2010 6:59 pm

Good flippin grief. It a lake in a rift that made the news recently when the northern section ruptured for a length of 35 miles near Dabbahu volcano up in Ethiopia. All the talk then was about the “New Ocean” that was just around the corner.
Africa is not well known for it’s extensive seismic network. Just a few days ago it was reported that Mikeno volcano in the Congo had erupted and killed dozens of people. Turns out it was actually a landslide associated with river flooding and that 46 people had died…. the volcano remains quiet. Some of the volcanoes near there erupt and no one knows about it for days or months.
A quick dig around the USGS site at http://earthquake.usgs.gov/earthquakes/eqarchives/epic/epic_circ.php yields at least 12 earthquake following the axis of the lake since 2008. Magnitudes: 3.9, 4.7, 4.2, 5.2, 4.6, 5, 5.5, 5.3, 4.5, 5.2, 4.5, 5.1. And to top that off, a cluster at 2.43S – 28.88E of about 14 with the largest being about Mag 5.9.
Not seismically active… yeah, riight.

Rich Matarese
May 19, 2010 7:20 pm


Damn. Mr. Watts, would you please strike that 6:29 PM post of mine? Glitches….

REPLY: OK feel free to repost -A

Greg
May 19, 2010 7:34 pm

Lake Baikal is the largest. Lake Superior is 2nd largest. L.Tan. might be 3rd. By volume. Cheers, gm

Pat Moffitt
May 19, 2010 8:10 pm

BillD
As a lake ecologist perhaps you missed the work done by the FAO’s Lake Tanganyika Framework Fisheries management Plan and the incorporated ecosystem management strategy paper by NKOTAGU, H. H. which states:
“The lake faces a number of threats including excess sedimentation, over – fishing,
pollution and habitat destruction along with climate change.”
As I posted earlier the lake has seen eutophication in the near shore waters and increasing oligotrophy in the pelagic areas (can cause problems with the lipid proxy used for T). Also see: Cohen, A., Bills, R., et al. (1993). “The impact of sediment pollution on biodiversity in Lake Tanganyika” Conservation Biology 7(3) 667-677
And the Lake Tanganyika Regional Fisheries Programme (TREFIP) ENVIRONMENTAL IMPACT ASSESSMENT REPORT -GCP/INT/648/NOR Field report which found “Bottom friction and water temperature play secondary roles in driving the hydrodynamics of the lake. Relatively high temperatures make the viscosity of Tanganyika’s waters low as compared to those in temperate regions.”
Another paper in the FAO document by Sarvala et al cautions “Fish production is ultimately dependent upon food production, and thus subject to climate-induced changes. However, the path from hydrodynamics to fish yields is
long and direct links may be difficult to identify.” Lake Tanganyika’s primary production dynamics may be uniquely complex .
The researchers claiming a CO2 temperature link and implied danger to the fisheries may have also missed Sarvala’s finding that:
“Neither could fish catch changes be linked to long-term trends in copepod zooplankton. Between-region comparisons also failed to show a direct connection between fish catches and food availability.”
Or the findings of Reynolds et al RESEARCH FOR THE MANAGEMENT OF THE FISHERIES ON LAKE TANGANYIKA GCP/RAF/271/FIN-TD/97
“Ecological studies and catch surveys have shown that production rates fall within the average range for deep tropical lakes, and are indeed not particularly high. These studies have also evaluated the vulnerability of the fish stock to increased
fishing pressure and possible over-fishing.”
So it would seem this recent paper highlighting temperature impacts on the fishery production may not have been a proper assumption- (There have been papers by Coenen and by Mannini that show SOME temperature correlation.) This study also found evidence of severe over-exploitation of the fish stocks.
The CO2 as “cause” simplifies the complex and in so doing prevents us from understanding. The Reynolds study concludes with far less hubris:
“Inter-annual, seasonal, and areal variations in yields within
Lake Tanganyika may be linked to the complex relationships
between fish stock fluctuations and migrations and the incidence
of nutrient upwelling and related plankton succession. Yet such
knowledge, even when coupled with findings from the wider set of
hydrophysical, limnological, and related studies that have been
conducted through LTR and other scientific investigations, by no
means allows for close ‘when, where, and how much’ predictions
of ecosystem fluctuation.”

Pat Moffitt
May 19, 2010 9:37 pm

BillD says:
I did both Google and Google Scholar searches on Patrick and did not find anything beyond blog posts. He suggests that adding nutrients might be a simple solution to the reduced productivity of the lake with a volume of over 18,000 cubic km. This solution has worked well in small salmon lakes with on the order of 0.001% of the volume of L. T. but fertilizing such a big lake and deep where nutrients are quickly lost to depth may not be a simple solution IMO.
Your right-I’m no “scholar”-but I had a lot of them that worked for me. I’m just a plain old graduate scientist with 35 years experience that doesn’t know enough to be quiet around my betters. I didn’t write papers- I wrote reports – my career was about trying to understand problems and fix them. If I didn’t fix them- I didn’t get paid or would be open to suit. I’m sure academics would be much more careful with their work if the same applied.
So de-carbonizing the industrialized world and “changing civilization as we know it” is easier than fertilizing Lake Tanganyika? (The salmon projects were demonstrations and showed no limitations as to scale. The real point with the salmon is there are tens of millions to study salmon problems but no money to start full scale fertilization program that is a known fix. A solved problem however has no academic value. There is actually a counter-incentive to fix environmental problems.)
I stand by my comments- the problems faced by the Lake and the people are complex- dismissing what we know about overfishing and trying to simplify the ecosystem dynamics to temperature is counterproductive if not reckless.

May 20, 2010 12:00 am

Nigel Harris says:
May 19, 2010 at 10:34 am
I’m going to have to try to find another site where I can find genuine, scientific scepticism about AGW, not uninformed knee-jerk condemnation of other peoples’ work.
so because we chuckle at people who still blindly thrash about like Don Quixote De Lamancha against the windmill when their theories have been proven to be full of lies and are ludicrous, we are bad people because we use critical thinking skills and figure out for ourselves rather than following the mantra of the dogmatic liberal?
And they say the skeptics are anal and have no sense of humor.
speaking of humor.
http://www.skepticalscience.com/Unprecedented-Warming-in-Lake-Tanganyika-and-its-impact-on-humanity.html
John Cook from “Skeptical Science” blog was kind enough to give the entire article about Lake Tanganyika and right smack at the top there is a pretty little chart. Does that chart look even vaguely familiar? I looked from top to bottom of this thread and I didn’t see anyone else mention it, so I thought I would.
These people are saying this is unprecedented since the time of the Medevil warming period. Well it was hotter then than now but mysteriously the chart on the right is far higher than the time of the MWP, or even the Holocene optimum several thousand years before then. So what exactly happened to those herring back then? Was there a medevil fish hatchery truck that went around dumping herring back into the lake system after the warming period was over? Did the fish adapt? One would assume so since these lakes have had fish since Biblical times since the Bible talks about large amounts of fish in the seas around Galilee. Did the fish get out and crawl to another body of water then crawl back to the lake when temperatures were more to the scientists liking of the day?
I know these are all things below the lofty mentality of the warmist scientist but they are common everyday things that just make their science look “unbelievable” at best.
I must also say the warmists are a little slow on the uptake of getting the gospel of global warming out… you guys have been talking about it since yesterday, skeptical Science just got it out today.

Billy Liar
May 20, 2010 4:53 am

Mike says:
May 19, 2010 at 11:32 am
Billy Liar said (May 19, 2010 at 10:28 am): “Seems to me that an ill thought out press release can do a lot of harm to your reputation as a scientist (assuming you have/want one).”
Good point. You might be interested in this.
How not to write a press release – gavin @ 21 April 2006:
http://www.realclimate.org/index.php/archives/2006/04/how-not-to-write-a-press-release/
———————————————-
Mike, many thanks for the link. I did find it interesting; I’m reading the comments too.

Henry chance
May 20, 2010 11:44 am

However, as Lake Tanganyika warms, the upper waters of the lake become less dense. Therefore, stronger winds are required to churn the lake waters enough to mix the deeper waters with the upper layer. As a result, the upper layers of the lake are becoming increasingly nutrient-poor, reducing the lake’s productivity.

So if I give her a sample of water from the deep and another 1 cubic meter sample from the surface, she can tell which came from the bottom? Warm water rises. She appparently didn’t test for differences is waves at different temps. You can’t compare fish output with the Great Lakes because they freeze over. Cuts into suface algae there also.
I read so many little comments in her opinion piece that are all about what she feels is going on. If the cores were drawn at the deep part, how do they compare with dozens of cores taken in shallower water? Ooops. She just has 1 core sample?

Pat Moffitt
May 21, 2010 10:33 am

BillD says:
May 19, 2010 at 6:23 pm
I did both Google and Google Scholar searches on Patrick and did not find anything beyond blog posts.
I’m wondering why you do not use your full name? If you need my CV I’m more than happy to provide and perhaps for your comfort some academics who know me.

Rich Matarese
May 21, 2010 12:00 pm

Writes BillD:

“I’m wondering why you do not use your full name? If you need my CV I’m more than happy to provide and perhaps for your comfort some academics who know me.”

Bill, it’s not only not necessary to provide one’s vitae in fora like this one but in a particular way quite perverse.
One of the adverse factors with which human beings must always deal in discourse of any kind – and scientific discourse is no exemption – is the logical fallacy of argument from authority, where credentials are used as clout. There is a temptation to conduct a sort of “pecker contest” in which the background of a disputant is used to clout an opponent instead of obliging reliance on lucid argument based upon supported assertions.
What gets posted in venues like this one can be more valuable than the usual-and-customary academic cockfighting that establishes which professor gets to crow at the top of one university’s or professional society’s dungheap, for the level of personal anonymity imparted by an online nickname compels the individual to attend to the intrinsic validity of his statements while at the same time freeing him from what are, in truth, quite damnable limitations required by the need to get a living.
Bear in mind that when John Locke (yet another physician) published his Two Treatises of Government – the second of these being undeniably the “crib sheet” from which our Declaration of Independence was written – he did it anonymously. And when Trenchard and Gordon later uttered their series of Essays on Liberty, Civil and Religious, they did it using the joint pseudonym of “Cato.”
Thus we speak today of Cato’s Letters, bound collections of which could be found in roughly half of the personal libraries in the American colonies by the time the bullets began to fly across Lexington green.
If you try to use your curriculum vitae as a club in this forum, you will not only be defeating the purpose of this kind of discourse but cheapening yourself to do it.

Pat Moffitt
May 21, 2010 2:08 pm

Rich Matarese
You may have the order of comments mixed up. BiilD started off a refutation to a comment of mine by saying he did not find my name in a “scholar” search – implying as such my comments were without merit. Not only an obvious appeal to authority but an attempt to restricting knowledge, scholarship, merit etc to those that publish academic work -rejecting those who labor in the equally challenging practical applications of science. While I agree with your comments on a rational level- it does get tiresome if not irksome at times. The need (and consequences) for anonymity of the Cato letters is far different than a blog. I don’t have a problem with anonymity- but little tolerance for those that snipe at qualifications while hiding their own. We all have our buttons.

Rich Matarese
May 21, 2010 3:40 pm


Pat Moffitt concludes his recent post with:

“While I agree with your comments on a rational level – it does get tiresome if not irksome at times. The need (and consequences) for anonymity of the Cato letters is far different than a blog. I don’t have a problem with anonymity- but little tolerance for those that snipe at qualifications while hiding their own. We all have our buttons.”

Given that our Mombasa Messiah and his sputniki have been making much in recent months of their desires, plans, and goals with regard to “Internet fairness” – in actuality, the active governmental suppression of dissent and information flow online – I think that we are in very much the same condition as had been experienced by John Locke, by John Trenchard and Thomas Gordon, by Richard Overton, by Algernon Sydney (who literally went to the scaffold for having uttered his Discourses Concerning Government).
We are really not in a purely scientific exchange here, but rather in what is a truly political discussion. What is posted on this Web site affects – even if only in a small way – decisions being made in the capitols of nations. I need not remind you of the pernicious impact upon government policies that has been imposed by the anthropogenic global warming fraud, nor of the effects we have seen over the past six months in particular as the result of the work of Internet gadflies like McIntyre, Delingpole, Monckton, and Anthony Watts.
Anonymity, pseudonymity – these are all valuable, reasonable, necessary protections for people here and now. We are not living in an era when the private citizen may simply speak his mind to the greedy, the powerful, and the corrupt without very real efforts being made at his utter ruination by those who serve the forces of corruption and political power.
Beyond that, however, it must be understood that a disputant’s qualifications are irrelevant when it comes to speaking sense. This is true not only of those who seek to flaunt their credentials as if these provided real, meaningful support for their
ex cathedra assertions but also for those who “snipe at qualifications while hiding their own.”
Any such “snipe at qualifications” is, after all, just as lacking in validity. Not so?

May 21, 2010 6:31 pm

I don’t think one necessarily need a PHD in Climatology to disprove global warming or a number of issues.
I myself do not have a PHD in anything however I have done a lot of research and I have a wonderful BS (Bad Science) detector and when see and hear things that don’t make sense to me, I refuse to back down to a bully in professor’s clothing.
I have a wordpress blog so if anyone really has to know my name that badly one can also click and click again to see my ugly mug and my name.
I think to harass someone because you doubt his name and credentials is to be a pompous windbag and not serious about debate!
History tells us that the sciences were for all with an education, the only people never included by Plato or Socrates were those who were uneducated because they didn’t care or weren’t able to be educated. Today anyone is able to be educated, from those who were given full scholarships to Harvard by their communist mentors like President Obama or like myself who has gone into major debt and almost died twice in the last 3 years due to poor health conditions from working too much and staying up too late doing research and homework.
Don’t you dare tell me that I don’t have the ability to carry on a conversation about global warming merely because I don’t have a PHD. What you aim at one person here, you aim at all, be forewarned.
Any refutation of a good and valid point or set of comments based on mere ad Homonym attack or Red Herring flinging only increases the ignorance of the accuser in the eyes of the masses.

Pat Moffitt
May 21, 2010 8:43 pm

Rich Matarese
you have really got to read the chronology of the posts–as I used to say to my parents- it wasn’t me who started it

May 21, 2010 10:52 pm

Part 1.
I have been researching this whole issue for the last couple of days.
At someone’s suggestion I went to check out the following article but unfortunately they only provide Abstracts through ProQuest and I can’t afford to sign up for their membership. Hydrothermal vents in Lake Tanganyika, East African Rift system
Pflumio, Catherine, Castrec, Maryse, Boulegue, Jacques, Gente, Pascal, et al. Geology. Boulder: Jun 1993. Vol. 21, Iss. 6; pg. 499
One would think that if there are active thermal vents that we’ve known about since at least 1990 this could have something to do with the issue.
It would also appear that there is a massive overharvesting of fishing going on that makes the gillnetting/long lining of salmon look like a drop in the bucket.
Also there is a massive problem with land use issues.
Granted the last two issues are man caused but have absolutely nothing to do with AGW.
I also read an article that shows that there have been higher than normal wind conditions which inevitably dry out the surface which is going to cause conflicting temperature anomalies.
I’ve also read about Gustave the killer Croc which could be eating up large amounts of fish. A much more viable option than AGW, especially since the authors admit that they only took two samples from a huge body of water. http://search.ebscohost.com/login.aspx?direct=true&db=f5h&AN=38995750&site=ehost-live
The above is a link to a scholastic database of a National Geographic Article.
Is an interesting article about how the two major species of fish have major variances in population.
Limnological variability and pelagic fish abundance
(Stolothrissa tanganicae and Lates stappersii)
in Lake Tanganyika
P.-D. Plisnier Æ H. Mgana Æ I. Kimirei Æ A. Chande Æ L. Makasa Æ
J. Chimanga Æ F. Zulu Æ C. Cocquyt Æ S. Horion Æ N. Bergamino Æ
J. Naithani Æ E. Deleersnijder Æ L. Andre´ Æ J.-P. Descy Æ Y. Cornet
Received: 24 June 2008 / Revised: 12 December 2008 / Accepted: 2 January 2009 / Published online: 2 February 2009
_ Springer Science+Business Media B.V. 2009
Part II –
The effects of windstorms on nutrient of Lake Tanganyka
Effect of wind induced water movements on nutrients,
chlorophyll-a, and primary production in Lake Tanganyika
V. T. Langenberg,1∗ J. Sarvala,2 and R. Roijackers1
1Aquatic Ecology and Water Quality Management Group, Agricultural University, Wageningen, The Netherlands
2Department of Biology, University of Turku, Turku, Finland
*Corresponding author: Aquatic Ecology and Water Quality Management Group, Agricultural University, PO Box 8080,
Wageningen, the Netherlands; Tel.: +31-629433225; Fax: +31-317484411; E-mail: victor.langenberg@wur.nl
Climate change decreases aquatic ecosystem productivity of Lake Tanganyika, Africa.Full Text Available By: O’ReiIIy, Catherine M.; AIinl, Simone R.; Plisnier, Pierre-Denis; Cohen, Andrew S.; McKee, Brent A.. Nature, 8/14/2003, Vol. 424 Issue 6950, p766, 3p; DOI: 10.1038/nature01833;
There have been numerous peer reviewed articles that have talked about an increase of fish, including the one above. The only species of Cichlids that are declining are the rock fish that are suffering from their habitation being destroyed by erosion of rock shelve strata by over use of the area.
Nature and Science are the only two journals that have any articles about global warming causing issues and they’ve been by the same authors, using similar test methods to this recent one. The latter not using any surface temperatures across the lake or more than two core samples. This lake is over 10,000 sq. miles.
That is like going to Alaska and turning a hair dryer on a patch of ice and taking only measurements of that patch and saying Alaska is suffering from an incredible heat wave.
After reading about 5 different peer reviewed articles. I see a trend Information from Nature and Science pretty much always push an AGW them onto Lake Tanganyka and other articles talk about the Chiclids thriving in certain areas and that high winds are changing surface temperatures in a cyclic nature during different periods of the 4 seasons.
the only thing anthropogenic that I can see is greedy African oil companies and massive overharvesting of fish populations.

May 21, 2010 10:54 pm

Of course that’s my humble non PHD, opinion of course.
I grovel at the feet of the masters and beg thy forgiveness and ask a boon of thee to permit my salvation for speaking within thy hearing?
grovel, grovel, grovel

May 21, 2010 11:09 pm

OK here is some more very interesting information.
Based on this information I would be very embarassed to have my name on the article that started this thread.
The thermal vents are putting off a tremendous amount of heat. I would strongly suggest googling the below article.
Thermophilic Sulfate Reduction in Hydrothermal Sediment of
Lake Tanganyika, East Africa
LARS ELSGAARD,l* DANIEL PRIEUR,2 GASHAGAZA M. MUKWAYA,3 AND BO B. J0RGENSEN4
Universite Pierre et Marie Curie, Paris 6,1 and Centre National de la Recherche Scientifique,2 Station Biologique de
Roscoff, F-29682 Roscoff; France; Centre de Recherche en Sciences Naturelles, Station d’Uvira, Uvira, Zaire3;
and Max Planck Institute for Marine Microbiology, D-2800 Bremen 33, Germany4
Received 21 October 1993/Accepted 18 February 1994
I just discovered this article that could possibly shed some light on this issue.
I know I’m no PHD but it makes one curious.
The Max Plank Institute is a pretty respected organization so it’s not like I’m speaking out of my ear.
I googled: Hydrothermal vents in Lake Tanganyika, East African Rift system Pflumio, Catherine, Castro, Maryse, Boulegue, Jacques, Gente, Pascal, et al. Geology. Boulder: Jun 1993. Vol. 21, Iss. 6; pg. 499
And I came up with the above article from the Applied and Environmental Microbilogy journal.

May 21, 2010 11:48 pm

This has some very interesting information in it that could also be a cause of any increased warming that would deny AGW
Science 313, 1419 (2006);
Pierre Sepulchre, et al.
Tectonic Uplift and Eastern Africa Aridification
DOI: 10.1126/science.1129158

May 21, 2010 11:55 pm

I’ve posted 5 articles in peer reviewed journals that are respected by both sides of the AGW coin in the http://www.skepticalscience.com/news.php?p=2&t=73&&n=201#comments thread.
They are so blinded by their religious worship of the AGW mantra that the best they could come up with is what is the wattage of the volcanic thermal vents?
Really? They take two core samplings from the lake bed from undisclosed locations with thousands of thermal vents in the lake bottom as well as volcanic tectonic shifting giving off heat trends in the area and the best they can come up with is what is the wattage of the volcanic thermal vents?
I feel like Christopher Lloyd in Back to the future 1…. 20,000 gigawatts? my gosh what was I thinking?
What is the wattage of volcanic thermal vents? “what was I thinking?”
Here I present 5 articles from well known and respected peer reviewed journals that present a viable possibility of other natural sources besides AGW and the best I get is what is the wattage of volcanic thermal vents.
Could they be playing a delayed April fools joke on me?

Pat Moffitt
May 22, 2010 8:11 am

1personofdifference
The claim by Tierney and others is that in this relatively nutrient poor lake- primary productivity is a function of upwelling of the nutrient stores from the lake’s deeper waters. The lake has a relatively low thermal (density) gradient meaning it takes a good deal of wind to disrupt the lakes stability and bring the relatively more nutrient rich waters to the surface.
Tierney assumes that winds are higher in periods of aridity (cooler periods) and thus lake productivity. Her cores assume that productivity is linked to biogenic silica (BSI) production– basically diatoms. Tierney shows a correlation between BSI and the TEX86 lake surface temperatures as support for the link between increasing temperature and declining productivity. Tierney assumes that the increasing water temperatures have led to greater stability of the water column making it both more difficult to turn over the water column and cycle the nutrients as well as reducing the intensity of the required winds. She draws on support from Verburg of increasing lake clarity as further evidence of declining production. She then links this decline in primary production to a possible decline in fish biomass.
There are a number of concerns with Tierney’s basic assumptions and best summarized in Victor Langenberg’s 2008 thesis (Wageningen University) On the Limnology of Lake Tanganyika:
-The highest productivity on the lake is found on the end with the lowest winds- contradicting a major premise of Tierney’s that productivity and lake stability are linked
– there is no measured evidence by Secchi disc that the lake has been getting clearer(less productive)
-There is no evidence of a climate and fish biomass link
-There is evidence of severe overfishing
-The simple association of wind speed and temperature lake stability and lake upwelling-is not so simple (A wind model in the hydrodynamics of the Lake showed that temperature is of only secondary importance-LT Regional Fisheries Management Programme)
-Found that allochtonous (outside the lake) sources of nutrients were more important than assumed by Tierney
-Found no evidence for a decline in lake productivity and that the lake’s current production is within the expected range for this type of lake
-Phytoplankton chlorophylla has not materially changed from the 1970s to 1990s
Tierney draws heavily on the BSI (biogenic silica index) as evidence for the TEX86 lake surface temperatures (LSTs) being related to productivity. She assumes that diatoms are a major component and a representative proxy for productivity from the work of Verbum. Langenburg contradicts Verbum’s finding that diatoms are an indicator for Lake Tanganyika productivity finding picocyanobacteria may be the Lake’s dominant form of phytoplankton. A 2009 paper in Journal of Plankton Research by Stenuite et al supports this position . A paper by Hecky and Kling 1987. Phytoplankton ecology of the great lakes in the rift valleys of Central Africa. Arch. Hydrobiol., Beih. Ergebn. Limnol., 25, 197–228 found that in Africa rift lakes upwelling is associated with diatom production and stratification stability with the production of cyanobacteria.
A presentation by Hecky and Verburg http://www.espp.msu.edu/climatechange/…/Physical%20and%20Ecological%20Responses%20of%20the%20Great%20 showed the switch from cyanobacteria in the wet season (warm) to diatoms in the dry season (cool) on an annual basis. The cyanobacteria do not appear as biogenic silica in the cores and as such will not be measured as productivity.
Tierney’s correlation of BSI with LST may be nothing more than diatoms being relatively more plentiful in periods of lake upwelling (aridity and high T) and cyanobacteria during periods of low upwelling (wet, low T and stable stratification). Tierney’s BSI as a result may say nothing about the overall changes in productivity of the lake. (The BSI simply reflecting the Lake’s primary productivity mode switching between cyano bacteria and diatoms.) Without a reliable proxy for total productivity the assumed correlations to temperature and fishery catch becomes less grounded.
You have commented on the heat from thermal vents- and direct you to comments made by Coulter (1968?) before the Banza vents were discovered. http://www.aslo.org/lo/toc/vol_13/issue_2/0385.pdf He proposed the possibility of heat flow at the bottom of the lake to explain the apparent lack of an expected salinity gradient and that given the depth of the lake and hydraulic residence time only small inputs of heat would be required to produce deep lake convection currents. Deep water generated convection currents would make the nutrient dynamics far more complicated than that proposed by Tierney’s simple wind/temperature mixing.
Tierney has acknowledged a “potentially” large role for overfishing in her Nature paper- however the media interviews have tended to diminish the relative threat of overfishing. There have been over two decades work trying to get the multiple interests and nations involved in the Lake fishery to agree to an enforceable/workable fishery harvest plan. Pointing a misguided finger of blame at global warming may very well undo these vital efforts. If so- the threat of global warming may have a far greater impact on the Lake and the food supply to its residents than any warming- real or imagined.

May 22, 2010 2:44 pm

I read one article that in the whole lake there is an expectation of 3,000,000 cichlids populating the lake. The expected harvest is 2,000,000,000. I know I’m no scientist but wouldn’t that be considered as over harvesting to the max?
Now you’ve got two different oil companies trying to get drilling rights on the lake and that’s going to screw up the environment even more. This is one area that you could point the finger at mankind. However it’s not AGW that is at fault here. It’s mankind’s quick attempts to point fingers where they shouldn’t be pointed to gain notoriety. There is over harvesting of the soil and plant/tree life, which is causing loss of rock outcropping which is a major home and foraging area of several types of cichlids in the lake. There are also now efforts under way to get drilling rights, which means for years there have been studies going on and this and that which has no doubt disturbed the environment. Now you have this team run by Tierney pointing efforts away from the fisheries to AGW. Does she not think that the fisheries agencies that have already showed greed and avarice aren’t going to take advantage of this?
Lake Tanganyika is suffering from an anthropogenic effect but it is not global warming, it’s stupidity personified.
Attention Pat Moffit, I would like to put your comment on my blog if you don’t mind.

Pat Moffitt
May 22, 2010 11:01 pm

1personofdifference says:
May 22, 2010 at 2:44 pm “Attention Pat Moffit, I would like to put your comment on my blog if you don’t mind.”
Not a problem
The important fishery in the lake are not the cichlids but the clupeids (a landlocked anchovy or herring) and to a lesser extent the latids (Nile perch type species). Most people don’t realize that there are mechanized purse seine fisheries in operation on this lake. It is really not known what the harvest rate is on the lake. I have seen estimates of high 20s to over 50% of the target biomass. All are too high.
I would be careful in calling the problems stupidity. It is actually following incentives— which may be perverse- but parsing this difference is not for this post. It is really hard to tell hungry people to stop fishing and difficult to tell the government sponsored factory ships to stop. Corruption in the US and corruption in some of the Lake’s adjacent countries operate on two different scales. It is a very difficult problem -especially given the population growth rates in this area -which are extremely high. Allowing all sides to blame it on climate however may make a a difficult problem next to impossible to correct.
I didn’t know about the oil exploration. My general feeling is that overfishing- especially highly mechanized- is often more dangerous to long term ecosystem health than is oil development. As an example- as bad as the Gulf BP spill may be- it is my opinion the spill can have nowhere nowhere near the long term negative ecosystem impact of the current shrimp fishery. (The impact of the oil is visible- shrimping is not- think of marine “clear cutting” where the trees don’t grow back) But again- another subject.